Dev Psych Test Prep

Development = Change over time

Orderly; follows a logical sequence

Cumulative; all that comes before + what comes next

Directional; moves towards greater sophistication

psychological, physical, behaviours


Development does not equal Growth

Qualitative + quantitative vs quantitative only

Qualitative includes quantitative


why?

develop effective methods of safeguarding children's development

Can't understand the present person, without understanding their past

To understand if a trait is genetic

Insight on origins of sex differences, gender rules, educational systems, antisocial behaviour

food and chemical affect on development


Development does not occur in isolation


Where?

Highschool: changes in start times.

Developing new curriculum, foster care system, law, court, medication


Prenatal - Prior to Birth

Infancy - 0-2

Early Childhood - 2-6

Middle Childhood - 6-12

Adolescence - 12-18


Processes (Domains) of Development

Biological: Changes in physical nature

Cognitive: Changes in thought, intelligence and language

Socio-emotional: changes in relationships, emotions, personality


Contexts of Development

Institutions, Physical environment, Families and peers, Cultural beliefs & Practices, Neighborhoods and communities


Central Questions

Continuity: nature of developmental change?

Sources of development: causes of developmental change?

Plasticity: can the course of development change, and to what extent?

Individual differences: why are people different from each other? How do they come to have stable individual characteristics?

Active/Passive Question: Are we passengers or active agents in our development?


Questions of continuity

Continuous vs Discontinuous: gradual vs abrupt

Quantitative vs Qualitative: changes in quantity vs quality, amount vs kind

Development is both continuous and discontinuous


Source of development question

Nature vs Nurture: Biology/Heredity vs Environmental

Both are incorrect and simplified

Interaction of biological and environmental factors


Question of Plasticity

to what degree and under what conditions, is development open to change and intervention?

Critical vs Sensitive Periods: Time when it is crucial for a particular feature of development to emerge vs Time during which it is optimal for the development of a particular function, but it is not critical.


Question of Individual Differences

How do people come to have stable individual characteristics?

What can past experiences tell us about a child's future?

Why are children so different from one another?

What makes individuals different from each other?

To what extent are individual characteristics stable over time?


Active/Passive Question

Active Theories vs Passive Theories: Children make sense of their world and determine their own learning vs Change in children is stimulated by the environment who is a passive reactor

Which view is right depends on theorist

Development proceeds as an interaction: Two-way influence


Keep in Mind

Central Questions

Mutual influence of biological, cognitive and social development

"Fit"

Normative development


Frameworks: way of organizing different theoretical perspectives on human development

Theory: A set of concepts and propositions designed to organize, describe, and explain an existing set of observations


Biological & Maturation Framework

Development occurs from within the organism as a result of the organism's biological heritage

Environmental influences take a backseat to biological influences

Theories:

Freud: Psychoanalytic/dynamic Theory (Psychosexual stages)

Erikson: Psychosocial Theory (psychosocial stages)


Environmental & Learning Framework

Development occurs from the environment

Adults shape children's development by rewarding and punishing behaviour

Learning is the process by which behviour is modified by experience

Theories:

Watson: Behaviourism (Classical Conditioning)

Skinner: Operant-Learning Theory

Bandura: Social Cognitive/Learning Theory


Constructivist Framework

Development is due to biological and environmental influences; occurs in qualitative shifts

Children have an active role in their own development

Theories:

Piaget: Cognitive Developmental Theory

Information Processing Theory


Sensorimotor: coordinate sensory perceptions and simple motor behaviours

Preoperational: represent reality to themselves through symbols. Mental images, words and gestures

Concrete operational: become capable of mental operations, internalized actions that fit into a logical system

Formal Operational: Ability to think systematically about all logical relations withing a problem


Cultural-Context Framework

Development is both biologically and environmentally influenced. Influences development through culture

Requires individual to be an active participant in children's development

Theories:

Vygotsky: Sociocultural Theory


Developmental Systems

Development is due to both biological and environmental influences and these influences interact with each other

Children actively influence the environments that influence their development

Theories:

Thelen & Smith: Dynamic Systems

Eccles: Goodness of Fit Model

Bronfenbrenner: Ecological Systems


Microsystem: Immediate

Mesosystem: Personal institutions

Exosystem: External Institutions

Macrosystem: Culture/Country

Chronosystem: World View

"IEXAO"

Those 500 questions we went through last week, so they're still relevant for today's lecture.


But what we're going to be looking at most likely almost what we'll be focused on today is going to be obviously that nature.


We'll be looking at genes, some of the basics, what are they, what they do, why you should care about them.


We'll also go through gene environment interactions and what we mean by that, especially under the kind of focus of relative psychology.


And we'll end with just a brief introduction of how we study gene environment interactions.


Now this isn't a biology class and I'm not a of part biologist.


I like biology. Okay, but we're not going. You probably won't even go as deep as your high school biology class went into genes.


It's just a refresher to kind of remind you guys what a gene is because it's not what you're writing on your legs.


All right, so again this is going to be a very drastic overs of when we talk about genes, right?


We've got, when we talk about this type of stuff, we've got our chromosomes, we've got DNA and genes.


And often these three terms are depending on who you're speaking to, used to kind of talk about the same thing or often get mixed up.


Obviously they are the name, but they are definitely not the same thing.


So we've got a chromosome, right? This is this red like structure. It's found in the nucleus of all of the cells in your body.


Each chromosome in a cell's nucleus consists of one molecule of your DNA.


The DNA molecule is a double helix which resembles that spiral staircase.


So those rungs of the staircase are what carries the genetic code that are made up of specifically paired chemical components called your nucleotide bases, right?


So you've got adenine, which is parody guanine which is paired with cytosine.


And everything about you is made up of those four nucleotide bases put together in to say random but with different pairs and orders.


Now it's that order or the order of those higher pairs that form the basic instructions or the code right Cell to create, not to create certain amino acids, proteins or enzymes.


And those are building blocks, different traits.


You might have each group of nucleotide bases that provides a specific set of biochemical construction in the gene.


Your gene is just a specific block, those nuclear type basins that kind of provide instructions to build this enzyme.


So that chromosome is a single molecule comprised of a very long, very large of helix.


Looking at the picture we have that cartoon of chromosome at the top area between the two lines, you can expand it in that cartoon picture.


Okay, we are at that again, very basic, very just a reintroduction fact.


Any biology students here good enough, Grade three level.


That's all I'm waiting for, just basic.


Speaker 2

All right.


Speaker 1

So again, what we have, the genes, are these basic units of heredity.


They're passed on from generation to generation.


There are over 40,000 genes in the human, in a human kind of body.


And these are 99ish or so percent of our genetic material.


With chimpanzees, which I always find fascinating, again, that 1% ish is what sets us apart.


Each chromosome, that double long stranded molecule of DNA contains thousands of genes.


So basically, genes are just particular centers of your DNA molecule.


Those chunks, chromosomes keep your genes tidy.


So I like to think of your chromosomes as kind of your biological faucet organism, hopefully where they're meant to be and how they're meant to be organized.


And each gene contains again those instructions for building a specific protein, you know, acid 1 enzyme.


So three consecutive thymine nucleotides form the instructions to create the amino acid.


O Alanine.


Speaker 2

Right.


Speaker 1

Phenylalanine. I did not do well in chemistry and some parts of biology because I cannot say words.


My tongue does not. I work with speech impedance. My tongue does not like to wrap around certain consonant combinations and vowel consonant combinations.


So I just stumbled over words all the time. Now a gene is expressed, if turned on, to make that specific protein, amino acid.


Speaker 2

Okay.


Speaker 1

Genes can be turned upon again, very basically turned on or off.


Speaker 2

Right.


Speaker 1

Based on various signals from within the cell. When genes are turned on, they cause what's called expression of that particular protein that they're coding for, just turning on or off.


This process is what differences between species.


Speaker 2

Right.


Speaker 1

So humans and chimpanzees, is that where that one is percent comes from?


So even though we share again a large amount of genetic material during, you know, that process, during developmental writings are turned on and off is very different.


Speaker 2

Between.


Speaker 1

The vault from some common ancestor a long time ago, you know, a couple few years ago.


Speaker 2

That's it, right.


Speaker 1

Have you guys ever seen the picture that Darwin drew of embryos?


Did anybody see that? So there's a picture of a garway through, I think it was a salamander of horse, a snake.


And up until a certain week in embryonic development, you can't tell species apart.


The embryonic, the kind of germinal to embryonic period is actually evoked very slow.


Speaker 2

Right.


Speaker 1

And it Isn't until I can't remember what week it might be is where you start to see the main changes of those species that actually physically start to see it is actually quite interesting.


We all know we used to have tails. That's why we also have like some vestigial, toxic.


I can say more of the words in psychology, not all of them.


All right, so where are your genes located? Like I said, and they are in almost all of the cells in your body.


All the creatures are made up of cells. Obviously, in plants and animals, there are two major categories.


You have your somatic cells, and you have your reproductive cells, your germ cells, your gametes.


In humans and other animals, again, gametes, the germ cells are the egg and the sperm.


These, besides, again, all other cells in the body are somatic cells.


Speaker 2

All right?


Speaker 1

The word somatic is derived from the Greek word soma, meaning body.


Speaker 2

Okay?


Speaker 1

So if you need somebody to help. Soma means so many. So, so many of your cells are somatic cells. Now, this is because only germ cells include. While germ cells only include the egg and the sperm.


Somatic cells encompass an enormous variety of other types of cells in the body.


Every other kind of part of you are somatic cells, your guts, your neuron cells, your skin cells.


And when we talk about them, each somatic cell contains all 46 chromosomes that you possess.


So each amount of cells contains your.


Speaker 2

Complete.


Speaker 1

Pairing of chromosomes. Remember, you have 46 chromosomes, or 23 pairs.


Speaker 2

Okay.


Speaker 1

When we talk about your jurocells, again, these give rise to, again, this is sterling, the egg yoga.


These are specialized for sexual reproduction.


STERM cells contain 23 chromosomes. So they look the best half of your genetic material.


And this is why we need both of them. For human, 26 means 26. Termino, you get 23, you get 23. From the start, they combine for that total 46.


Speaker 2

All right.


Speaker 1

Now, this is kind of why they're all unique. Even identical twins, There will be differences, but generally they have.


They started out with the same chromosomes Material where they start to differ is on and off.


And some of that has to do with. Can have to do with environmental factors.


Speaker 2

Things like that, right?


Speaker 1

But really, we all started out as a single cell, which I think is a missing.


We start out as a single cell called the zygote, right?


Which consists of the egg fertilized by sperm. And so it's when you become that zygote that we then contain 46 chromosomes because each of your.


The contributing parts give half of their genital.


So all of you, think of one. Now, as viewed from a human perspective, nature seems to have done some ingenious engineering to overcome obstacles.


Again, the evolution of sex is an easy one to see. So to make them remove from asexual sexual reproduction, nature took a system by which parent cells reproduce simply to active fighting sexual reproduction and altered it to allow two parent cells to combine to create hospital, which is that sexual reproduction.


Now, this is the main difference between the somatic cells and the germ cells.


Somatic cells undergo MIT and germ cells undergo meiosis.


Speaker 2

Okay.


Speaker 1

One of the ways I've tried to get you to try to remember the difference is somatic has an ally.


So this is mitosis.


Speaker 2

Right.


Speaker 1

Somatic mitosis, meiosis has an E instead of an right here with the germ cells.


Okay, so just trying to figure out which is which.


How I try to remember. Helpful, not helpful. Are these things helpful or not helpful? Okay, I know it's really early today. Feels worse than having last moment. I think it's because you've had at least two full weeks of priming more information into your place.


All right, so again, somatic mitosis, the germ cells, gametes, meiosis.


Speaker 2

Right.


Speaker 1

All other cells in your body, identical size and those gamuts undergo mitosis.


The gametes are the only ones that don't undergo mitosis.


Speaker 2

Fire.


Speaker 1

So when we look at somatic cell duplication, theirogenetic material essentially just duplicates, divides a half, creates two parent or two daughter cell.


Sorry. With exactly the same genetic material in them as their parent cell.


So this is just replication, Direct replication and division.


Speaker 2

Right.


Speaker 1

So mitosis is the process in which the nucleus of a cell divides to create two new nuclei.


Each contain an SO spiromic ptosis. This allows the cells in our body to divide and regenerate.


Your hair, to grow, your skin, to heal after wound.


Almost all of the DNA replication in your body is carried out through the process of mitosis.


So this is just natural cloning. Now, on the other hand, germ cells undergo other diagram meiosis to produce beginnings where they duplicate their genetic material but divide twice to create four new cells with only 23 protons each.


But only the second step.


Speaker 2

Right?


Speaker 1

So it's duplicates, divides, and then they divide and separate.


So each gamete contains. That's right. Each gamete only contains after genetic material of the contributing parasite.


So meiosis is the process by which certain sex cells are created.


If you're a natal male, your body uses meiosis to create sperm cells, which we get in puberty and continues Rip in lifespan and each of the meiotic divisions in males produce four sperm.


If you're a natal female, it uses mimosis to create egg cells which occurs during the fetal females gestation.


It happens in utero.


Speaker 2

Right.


Speaker 1

Being presented in females at birth. Each meiotic individual in females produces one viable bullet and three that die off immediately.


So the fun fact for this week is that at 20 weeks a female fetus has a fully developed reproductive system.


Repeat 6 to 7 million eggs. So again, meiosis for males creates four viable sperm and only one viable egg.


And for meiosis I often think apathy or the creation of me.


How many chromosomes does a ova contain?


Speaker 2

Sorry?


Speaker 1

An ova an in half. This is 23. Okay, so an ova, the egg only congest to O3. The sperm only con G T3. That's why we need them to come together.


Speaker 2

Right.


Speaker 1

To complete the 46 repairs.


Speaker 2

Right.


Speaker 1

For each ring path one side of the staircase. That's probably not biologically accurate in the picture, but just so you can understand the pattern, how are you destroying them?


Right. It's my own psychological experiment.


Speaker 2

Okay, now.


Speaker 1

When we start discussing sex determination, what determines whether a given individual is male or female or male.


And trying to make a 23 pairs of chromosomal chromosomes found in the human cell.


The two chromosomes are of the same size and shape make a very corresponding genetic material for the chromosomes of the 23rd pair.


Speaker 2

Right.


Speaker 1

This isn't necessarily the case. This pair of chromosomes determines the person's genetic sex.


In females, both members of the 23rd pair of chromosomal same type in near the X chromosome.


Males however have 1x which is paired with a lot smaller Y chromosome.


This is in again normative development. You can get differences in which there's double X and Y and other variations.


But when we look at normative development is in X and Y or XX.


Speaker 2

Right.


Speaker 1

Any questions with this? All right, we're going to see if this place. So these are two short clips from a longer video again which is just going to go through some of what I've already said and probably add a couple extra things.


I will just mention that if you can, if there's something interesting.


I don't videos anything showing.


Speaker 3

People do all sorts of things to get attention and lie they made the last thing on his mind.


But this man's body is working toward this. Whether we're thinking about it or not. Our bodies want to make babies.


Speaker 2

And.


Speaker 3

Our bodies are very good at it. Around the world, about 355,000 new babies get made Every day.


But as ordinary as it seems, creating a new human being is no simple feat.


Just think of it. No matter who you are, once upon a time you look like this.


From a single cell, you built a body that had 100 trillion cells.


You made hundreds of different kinds of tissues and dozens of organs, including your brain.


That allows you to do remark. How did you do it? Today we can look closer than ever before. Into the womb, into a cell.


Speaker 1

Into.


Speaker 3

The essence of life itself. Not only can we see what's happening, but now we're beginning to see how it happens.


The forces that build the embryo. The molecules that drive this remarkable change.


We're uncovering the most intimate details of how life is created.


The secrets behind life's greatest miracle.


Speaker 1

Sam.


Speaker 2

Think.


Speaker 3

All the people on this beach are just working on their summer pans.


But beneath all that sunscreen under the skin, there's a frenzy of activity.


Without even signify or. Almost all the adults here are busy trying to reproduce.


They can't help themselves. The urge to procreate is a fundamental part of life.


Not just for us, but for all life. Why is this urge so universal? At least somewhere, who can probably go to this DNA, the molecule that carries our genes, mechanical instructions for building our bodies and keeping us alive.


All wrapped up in a tiny winding staircase. DNA has run the show for more than 4 billion years for one main reason.


It's very good at making copies of Exile. The copies can get passed to a new generation in a couple of ways.


If you're a Bacterian, you might need a cloney making exact replicas of yourself.


All your descendants have the same DNA and except for occasional mutant, are just like you.


It's simple, it works. And genetically it's extremely boring. It can also be dangerous. If humans were all clones, everyone would have the exact same immune system.


And one successful parasite could wipe us all out.


Torchy Cran they're sex the method of choice for 99.9% of the organisms on earth.


More complex than bacteria. With sexual reproduction, two individuals each provide some DNA.


Most animals put it into sperm or eggs. If the two can get together, a new being will be created.


One that's different from its parents and everybody else.


Where there is sex, there is variety. And when it comes to survival of the fittest, variety has a death advantage.


All this comes with advice. Sexual reproduction may be, but it's also quite tricky.


To get an idea of how tricky, just take a peek inside a man's testicle.


It's packed with tiny tubes coiled in the bottoms Stretched out, they can cover half a mile.


Inside all this tubing, the average band is turning on thousand new sperm every second.


That's about 100 million new sperm every day and more than 2 trillion over lifetime.


And here's the tricky part. Each and every sperm is one of a kind, carrying a unique genetic package.


How is this possible? How can one person produce so many different combinations of genes?


The ants arise in a very special way. We make sperm and eggs, a process called meiosis.


In almost every cell of your body, you have 30,000 or more different genes spread out on very long strands of DNA called chromosomes.


Most cells have two versions of every gene on a total of 46 chromosomes.


Exactly half of those, 23 came from your mom and 23 came from your dad.


They come in pairs, where the partners are very similar but not quite the same.


The only time they get together is during meiosis.


Here's how it works. Inside a testicle that's making sperm.


Speaker 1

First.


Speaker 3

Each chromosome makes an exact copy of itself, keeping it attached.


At one point, they condense, creating an exit chip.


Now the chromosome partners get together and the two, or actually four, will embrace.


They cling so closely, big chunks carrying whole bunches of genes get exchanged between the partners.


The cell then divides twice, each time pulling the pairs apart.


The final result is a sperm or an egg cell with 23 chromosomes, half the normal number by itself.


The cell is incomplete, but it still holds incredible promise because every chromosome now carries a combination of genes that has never existed before.


All this gene shuffling means that within a single species there can be an enormous amount of diversity.


And the more diversity, the better the odds are that some and the round ball.


Speaker 1

So the first Claire could just pass the energy in case there's just about again a lot of what we already discussed.


And then this one is just called messages in your gene.


Speaker 3

For a gene to be turned on, something has to come in and loosen up the right section.


Then the sounds machinery can latch on and read the DNA.


The first step on the long road to building a protein.


Those molecules that can turn genes on play a key role in every aspect of development, including the process that transforms the embryo into a boiling or a kernel.


We didn't want to know. We wanted to do it, I guess, the old fashioned way.


Speaker 1

Or you could. We did a wedding ring test where you take a piece of your hair in the wedding band, pull it over, it moves one way in a circle and it's a girl and then straight one that's a boy.


And I said it was a girl. And there was a point when we went into the ultrasound where I was playing and said, well, we could look.


At this very moment, we could look and we could find out.


I said, no, no, no.


Speaker 3

By the time most ultrasounds are done, around 18 weeks or so, doctors can sometimes make up the sex.


But in the early weeks, it's impossible. Take a look at a seven week old emerald. Try to guess what sex. Think it's a boy? Believe it or not, this is not a penis, at least not yet.


It might become one, but it could just as easily turn into a clitoris.


The female sex boy. At this stage, boys and girls look exactly alike.


And not just on the outside. Inside there are two gonads, which could become testicles or ovaries.


And there are two sets of tubes, one in case it's a boy, the other for a girl.


Of course, there's one way to tell the difference.


Look at the chromosomes in a cell from the embryo.


One pair on only 23, he turns. An embryo with two X chromosomes usually becomes a girl.


If one of those X's is a Y, it will most likely be a boy.


Recently, scientists came up with a good idea of how this works.


There are only about 30 genes on the Y chromosome.


One of them is called sry. This gene seems to function just once in a lifetime.


Late in the sixth week of embryonic development, and only in one place, the gonad SRY turns on for a day or two and the cell churn out its protein.


But in that short time, SRY sets off a chemical chain reaction, turning on other genes, eventually turning the donads into testicles, which begin to make testosterone.


Testosterone travels throughout the body. If it reaches the genitals, then the cells here will build penis.


But if there are two X chromosomes and no Y, different genes get turned on and the gonads become ovaries.


The embryo becomes a baby girl. This is the power of genes creating cascades of chemical reactions, defining the form and function of all the cells in your body.


Sometimes genes send a message to multiply and grow.


As with the arm and leg bod, Sometimes the message is developed as it is a few days later to the cells between fingers.


As the weeks pass, the embryo's genes send billions of individual messages, constructing new kinds of cells and building organs.


And men. Two months after fertilization, the embryo is now called a fetus.


Almost all scorpions are replaced, though they're not working yet.


The whole fetus is just over an inch long and weighs less than a third amount.


Over the next six and a half months it will grow almost 400 times larger and prepare for birth.


All this demands a constant supply of nutrients.


Speaker 1

What would s. Or there was a certain type of. Of the dots. What did I use it as an example of? You remember the example, it was like a critical time, a critical period.


So remember I said there are critical periods in development when something has to happen in order development to occur.


And in humans, I said these were things for humans often contained in the prenatal period.


SRY would be an example of a human critical period in that one to two day kind of window in that late sixth week of female development.


If there is no XRPY that gets turned on and releases its chemical message, then what we tend to see is a female penis develop.


Speaker 2

Right.


Speaker 1

Now there are instances, there's a lot of interesting things that happen in biology and there are instances of.


In which potentially either doesn't turn on fully, so its effects aren't fully realized until puberty when there's another proliferation of testosterone for males.


And there are, I was here, there it is. There's a tribal individuals of peoples in faith, all of it up in which some of their male males don't have.


It seems that this might not happen during this period of fetal development and they develop as phenotypically female and so, so it's not holistically female.


There still are some differences. And it's when they hit that second kind of proliferation, that release of testosterone in male puberty that the phenotypic expression of male and sexual characteristics come out more.


And so again up to birth, if we're going to see a needle male sri SRY is usually done what it needs to do during that kind of.


So SRY doesn't determine male or female, it only determines male.


And if it doesn't happen, then the baby's human. So it's only. It only exists on the Y chromosome. And so if there is no Y chromosome, there is no sry.


Speaker 2

Right.


Speaker 1

But again, as I said, we can have an xxy, so an XXY female.


So there are genetic variances that we see when we look at that level.


And again, depending on what happens during some of these kind of characters, as it appears, their phenotypic expression may be different or show similarities to the female characteristics.


It may be more slightly masculinized. It's one of those science. Again, I know I keep saying it and I know it's too early on a Monday to be excited about something, but if I could have gone to ship down a genetic rabbit hole, the mind has to be as well.


But yeah, so there's a lot of differences. But again, I'm going off track. We stick with the normative human developments.


Just when we have X, Y or XX as a distance, that means only with the Y, if there's no Y, there's no test on Y, there is no influence.


Again, it's not the same that X X individuals don't have testosterone.


It's just not to the same level and not to the same influence.


And I'll explain what I mean by phenotypic expression.


Speaker 2

Okay.


Speaker 1

Any other questions? Anything that you saw that is just a good example of what I was talking about.


And I also, one of the things that is interesting is that our bodies often produce more than what we end up eating.


So as the video pointed out.


Speaker 2

The.


Speaker 1

Fetus has the material to be either genetic cry or genetic peanut until it is told by its form, by its, by its genes to be one or more.


Speaker 2

Right.


Speaker 1

To phenotypically express as one will or as we know, a combination can also happen.


Speaker 2

Okay.


Speaker 1

And as I said, when we look at the prenatal period, you'll see this next week with the hands, we develop web techniques, we develop web paints.


Speaker 2

Right.


Speaker 1

In Europe, we have wet, we have material between.


Speaker 2

Right.


Speaker 1

And again, it's. Why would you need to develop the extra stuff and then tell it to turn it off?


Because our genetic material is not that different until certain like turning on and turning off from other species.


Speaker 2

Right.


Speaker 1

And we have homologous kind of hands.


Speaker 2

Now we can.


Speaker 1

Organs and fingers and limbs.


Speaker 2

Right.


Speaker 1

But until again, the human, our human part of our pro turns on.


We could have names, we could have clippers, all of these things.


Whales are mammals. They don't have fingers. But when you look at the bones, they look like our red purples and our red fossils and things like that.


I'm sciencing it. I'm sorry.


Speaker 2

Okay.


Speaker 1

All right, back to the topic. Okay, so how do genes detect determine our traits, the physical traits, our psychological traits?


Well, most genes come in several different forms, and these forms are called alleles.


So an allele is just a specific form of a gene that influences a particular trait.


It's one possible form of a gene that may occupy a particular location on the chromosome.


Just as A child inherits 23 chromosomes from the maternal and paternal side, the child also inherits one version of each gene, one allele again from each contributing parent.


So you have two alleles for every gene. If you have the same two alleles, you could give them the same one from each Contributing parent.


Speaker 2

Right.


Speaker 1

You're said to be homologous for that homozygous blob.


There's the word I'm looking for. Homozygous for that specific gene. Is that a number?


Speaker 2

Right.


Speaker 1

If you have two different alleles for that specific gene.


So each of the parasols provide the different or your heterozygous.


Whether the allele parents are homozygous or heterozygous affects the characteristics of the phenotype.


Our phenotype is the observable physical, behavioral, psychological trial traits that the individual actually develops.


Your hair color, your skin tone, your psychological makeup.


And these result from the interaction between the environment and a person's genotype.


Your genotype is your exact genetic makeup to ignore particular genes that you inherit, your complete set of genes that make up your forerunner genotypes.


Speaker 2

Right.


Speaker 1

A phenotype is how they express themselves, how their genetic makeup is expressed.


So what does homozygous and heterozygous actually mean?


When we talk about phenotypic expression, if we look up, if we look at kind of made up example, you'll use hair color.


Now let's imagine hair color is determined by a single gene, which is not true, but we're going to ignore that.


Let's just pretend hair is made up from a single gene.


Speaker 2

Okay.


Speaker 1

We're going to also ignore environments. Ethanol sound like chemical ways of changing hair.


This imaginary pair gene has 2, 2 alleles, pink and blue.


Speaker 2

All right.


Speaker 1

If you are homozygous for this straight, what does that.


Right. Both are the same color. So you're either going to have pink hair if both of the parent cells gave you pink alleles, or you're going to have blue hair because both of the parent cells gave you blue.


Okay, if you're heterozygous, what does it mean?


Speaker 3

One each.


Speaker 1

Now, I did call it three individuals in the room. What happens when we mix things?


Speaker 3

Blue.


Speaker 1

Is usually what we think of couple of genes. It's not that simple. That's nothing else. Now again, if we're looking at humorous verbosity, this can actually have several different effects depending on the specific trait or the gene that we're talking about.


So one of the alleles is what's called dominant. This means that its chemical instructions are always followed.


Speaker 2

Right.


Speaker 1

Whereas instructions for the other part of that recessive allele are ignored when paired with a dominant protein.


But recessive genes are still passed on.


Speaker 2

Right.


Speaker 1

To future generations and can be expressed in the event that they're paired with another recessive gene with Another recessive allele, recessive recessive gene.


And so a person can become a carrier of that recessive gene.


So if paint is gone in the previous example, what would happen?


What pair of color would it happen? However, this isn't the end of the story, as your hair may be affected in other ways.


Sometimes one alfield does not dominate another completely.


This is a situation where in which it's called incomplete dominance.


In this case, both alleles contribute to the expression of the trait.


And so the trait is expressed somewhere in the middle of the homozygous dominant and the homozygous receptive.


And so essentially this is the intermediate of the two phenotypes.


The osprey will show a variety of phantom types, but each one will lie along the continuum bracketed by pink to blue and everywhere in between.


Again, if you want to stick with color, you're going to get different shades all the way to pink mixing into purple, mixing in to the vibrance of blue.


Speaker 2

Okay.


Speaker 1

Again, this means that neither allele compare is dominant, but they confine and display the tree.


Now, the easiest one would be purple, where you're expressing both of them mixed together.


Now, a real world example of this is sickness cell anemia.


The allele of the sickle cell is dominant and the allele, sorry, allele for normal cells is dominant.


And the allele for sickle cell is recessive. If homozygous, so recessive, they will develop sickle cell disease.


So if you receive both recessive sickle cells from each parenting cell, you will develop sickle cell, which means that your red blood cells will be abnormally shaped in that sickle cell shape.


This also means that it reduces oxygen right in the body supply of oxygen.


And because of the shape of the sickle cell blood cell, they tend to kind of come together, which can involve smaller blood vessels, damaging organs, causing pain.


Speaker 2

Right.


Speaker 1

Now, because of the characteristics sickle cells called, so there's a lot of complications and health risks that come with having the homozygotes for sickle cell anemia.


But those who are heterozygous for sickle cell, so they have one dominant neural gene, one recessive allele.


They have, they can have what's called sickle cell triggerism, right?


And in most situations, these individuals have no problems, except maybe if they are seriously short of breath, they may suffer temporary, relatively mild recalls of the disease in a higher altitude.


So again, they don't necessarily don't have sickle cell anemia, but there may be some trigger.


But often if there's Other environmental exacerbations of the situation.


Now, there was an advantage of being heterozygous.


These blood shapes are resistant to parasites that cause malaria.


There was a evolutionary reason for phenomenal.


Now there's a third potential outcome. And this is when both alleles contribute to the trait outcome.


But the outcome is completely different.


Speaker 2

From.


Speaker 1

Both of the contributing allegories. So they're not mixing like they did in the, you know, incomplete predominance.


What we tend to have is co dominance in this situation.


So rather than displaying intermediate characteristics, the child will fully express the characteristics associated with each of the the two alleles.


Again, when the effects of both alleles are shown, this is said to be co dominance.


So when you breed a white chicken with a black chicken, both of which are dominant genes, the result is not a great chicken, but often a chicken with both black and white feathers.


Your text will use. It uses the blood type as an example.


Speaker 2

Right?


Speaker 1

Your AB blood type doesn't become half an A, half a B and match whatever that would look like as a letter your ad.


Speaker 2

Okay.


Speaker 1

So each of the blood types is fully expressed in av.


Speaker 2

Yes.


Speaker 1

Does that make sense?


Speaker 2

The differences? All right.


Speaker 1

But of course, we're talking about genes, and nothing is so simple as one gene coding for one trait.


Very few genes, very few traits, especially behavioral traits, are directly determined by one gene acting alone.


Most genes are what we call polygenic. So traits are determined by many genes that serve an influence on the trait in question.


You can use the analogy of a poker hand, right? So imagine you have a poker hand. Your poker hand is a trace, right? And you can have either a winning hand or a losing hand or somewhere in between.


Each of your proper hand has five cards that contribute to their hand.


That winner or that losing hand. No one card determines solely whether our hand is going to be a winner or a loser.


That's essentially the idea of the team polygenic traits.


No one gene determines solely what the trait is going to look like as well, you have to keep in mind that the effect of any particular gene or set of genes is probabilistic in nature.


Meaning you can't predict what the exact outcome is going to look like based on only one gene or even a set of genes.


And this is because they represent the probability or the potential for a broad range of genesis outcomes along a continuum of probability and possibilities.


Speaker 2

Right?


Speaker 1

So again, if you think back to poker hand, you can't tell the effect of any particular part of whether the whole thing will be good or bad just because you have an AC doesn't necessarily mean that you're into a dear learner.


All of that is before we even start to take into consideration the impact that the environment has on our phenotypic expression.


Speaker 2

Right?


Speaker 1

Because again, in poker, it depends on the parts that the other players have as well.


So nothing is simple. Does that all make sense, though? How are you guys doing? Do you want. This would be a good place to have a short break if you want one.


Speaker 2

Yes.


Speaker 1

Let's have fun. We'll come back and.


Speaker 4

Or what we'll refer to as gene environment interactions.


What this means, based at the basic level, is that heredity is not destiny.


Not in fully. Not fully.


Speaker 5

Okay.


Speaker 4

When discussing gene environment interactions, an important distinction to make is between again, the genotype, which I mentioned, and the phenotype, which I mentioned, just to reiterate, right.


Your genotype is all the internally coded inherited information which is stored in almost all of the cells in your body.


It's used as your blueprint, or again, that set of instructions for building and maintaining that they are.


Your genotype is your exact genetic makeup, again inherited from both of the parent cells.


It is your unique genome. This would be the kids genome sequencing. You can't really see our genes right now. Like I can't look at you and see them, but I can see the phenotypic expression.


And so when we're talking often about hair color or traits, what we're often discussing is the phenotypic expression of those genes.


All of the kind of observable characteristics. Again, it's the behavior of the physical, psychological characteristics that we can observe and measure.


So this can include your height, your eye color, your disease history, how your body deals with the cold.


Speaker 5

Right?


Speaker 4

And even your behavior and your general disposition.


All of these can be seen in a direction. This means that we can observe your phenotype. Now, from the first part of the gene selection, we saw that genetic effects are complicated.


This is because again, they're polygenic and they're probabilistic in nature.


Things get even more complicated when we add environmental effects into the mix and try to determine how genetic effects and environmental effects interact combine to influence human development.


So some principles to keep in mind when we're considering the gene environment interactions, the first thing that needs to be mentioned is genes and what we think of as environments.


School, friends, family, don't actually interact with cells.


Speaker 5

Right?


Speaker 4

Even though the diagram says they do. Remember, your genes are hidden away in cells and they're pretty well protected.


So when we talk about interactions, we're often talking about phenotype environmental interactions rather than literal genotype environmental interactions.


However, changes in the phenotype region based on this interaction do affect changes in the genotype.


And this is through gene expression. These genes can be turned. Remember, they can turn on or off. Therefore, researchers often use the gene, the gene environment shorthand, whether it's talking about this.


And this is also. We use that shorthand so that we don't have to discuss all the levels in between, especially for this course.


Speaker 5

Right.


Speaker 4

I just, I'm just Going to be talking about the kind of the genie environment.


I'm not going to be looking at all the in between that we would have to discuss to get between those two.


This is not a biological class, but do understand that those are just as important and necessary.


It's not for this particular class. Now, one of the problems with sorting antiques is and the environment during measures that genes in part determine the environments in which people are exposed so people will seek out to create for themselves.


This also links kind of to that. Back to the passive question right here. So there are three types of relations between heredity and the environment.


The first relationship is passive, right? This is a passive environment. This refers to the association between the genotype the child inherits with their parents and the environment in which the child is viewed, is raised.


So the parents pass on both the genotype to their children, their child and also provide much of a thrilling environment supporting the expression of those kinks.


So athletic parents are those that have more abilities and more likely to transmit genes that make for more hepatitis children.


They're also more likely to be the parents that enroll their child in sports or some type of physical activity, or expose them to this type of activity.


Speaker 5

Right.


Speaker 4

So in this sense, they're providing both the genetic material as well as the environment to try to influence that genetic.


Same with parents that might be more artistic in nature.


They may expose their child to more different types of cr.


To more artistic types of activities and biases.


Now, again, in both respects here, the children, the child are passive recipients of their genetic makeup and the environments that they find themselves in.


And this passive, this passive type of relation is most common obviously in that kind of infant stage and the young child early childhood stage.


We tend to see this a lot. I used the example of athletic ability, artistic ability, but we also can see the transmission of antisocial or aggressive behaviors as well.


As a result of this, again, parents who have history of behavior, which tend to been found in some instances to be large and wearable, are at an increased risk, depending on social supports and environments, of potentially abusing your child or providing a less manuated environment.


Well, treatment, we do have sexual reviews. That happens.


Speaker 5

Now.


Speaker 4

The second relationship we're going to look at is what we call evocative or reactive gene environment deletion.


And this is where different genotypes evoke different responses from the environment.


So, for example, a social, active, even tempered infant is likely to receive more positive social stimulation from those in their environment and others in comparison to those that might be more passive or socially.


Speaker 5

Withdrawn.


Speaker 4

Child feels bright due to part to their genes. They may pay greater attention to their teachers.


They may ask more questions and in turn receive greater attention in school than children who aren't as inquisitive, who might be a little more shy.


You might not ask them questions. Another Although arguing with a spouse may result in somebody becoming depressed, it is equally possible that individuals who are prone to depression tend to revoke up against the difference between others.


Following this question, the direction of the effect.


This is the idea of I do something that invokes a response from my environment and that response from my environment can drive or hinder my development.


Speaker 5

Right?


Speaker 4

The phenotypic expression of that gene. So I could be all I know. It's a perfect analogy.


Speaker 5

Right?


Speaker 4

Again, because everything is apologetic and probableistic in nature.


It doesn't mean that a shy, quiet child isn't a bright inquisitive child.


It just means in certain environments they may not get attention if they aren't expressing that.


Whereas a child who does ask questions, who is engaged in that particular environment may get more app positive or potentially negative depending attention and that can have an impact on the development.


For example, within that environment, that's just looking not that's just looking at an an individual microsystem without looking into the rest of the programmers and ecological systems.


All right, see how I did that? See how I linked it back?


Speaker 5

Learning things. Okay.


Speaker 4

So in their third type, this is the active gene environment relation.


Here individuals are actively seeking environments related to their genetic makeup.


So this type occurs when an individual possesses that propensity or skill to select certain environmental exposures.


This is when the child starts actively picking and seeking out environments.


Speaker 5

Right?


Speaker 4

So example, the intelligent, highly motivated child may ask you place in honors classes.


The strong, coordinated, aggressive child may want to join.


Athletic teams may ask to do so. Or the last academic or athletic child may choose to be, you know, may choose to be who are introspective in nature.


Maybe they choose to join depending they're on the antisocial side of things, a more deviant peer group.


Essentially, we gravitate towards environments and activities that reinforce our own behaviors or choosing these.


So this process of development, deliberately seeking environments that fit our horrendous, also known as niche picking or niche construction, is first seen in childhood, becomes obviously more common as we get into later childhood, middle childhood, adolescent adulthood.


Any questions about this? Now, even as adults, sometimes you have no choice, right?


So I like kind of said that you seem more passive than evocative.


You seem more passive in that early Stage of development, right?


Evocative. Also early and then active becomes a little bit later.


Start pe. There are times you have no choice. You have to be in an environment somewhere. So you still have to be part of that passive when you're just there, right.


We always interact. I would argue this is my personal opinion, is that we always have an impact on our environment.


Even if you're quiet, as long as you're there, there's an impact you have on that environment.


So there's always an evocative kind of relationship with our environment.


Speaker 5

Right.


Speaker 4

And it can impact us. And then obviously as adults, we become, as we get our autonomy and our own agency, hopefully better able to to pick to be active in where we want to spend our time.


And why tire does that make sense? This is driven by your heredity, right? By your genes to some extent. Now, teams and the environment verdict influence development on their own.


Again, they interact. Experience is determined which phenotypes emerge and genotypes influence the nature of children's experiences.


So to understand how the genes influence development, you need to look carefully at how environments work as well.


So what we see is that the relationship between genetic and environmental influences is not a one way shoot, it's bi directional.


Even though our genes affect the development of our traits and our behaviors, our traits and behaviors, they also kind of prompt certain kinds of responses of our people that lead us to place ourselves in certain environments.


These environments, specialized school, after school programs, the museums, the theater, watching certain TV shows, engaging in certain TV programs, all of the different things you might be interested in and do all affect the manner in which genes are expressed.


Our development reflects continuing bi directional exchanges between our genetic heritages and the environments in which we find ourselves and place ourselves in.


This highlights the fact that there are multiple, multiple pathways and trajectories along which an individual might develop that nature which are combined to determine these pathways.


And that either genes or the environment may limit the extent to which the other factor can influence development.


Again, it's a probable listen, right? You can have the most intelligent child ever in your not.


If you do not provide them with any environmental stimulation, they are unlikely to reach their full potential.


Even with, you know, you might think you have a smart child, you give them all the environment.


What we do is we try to maximize what our genes give us through providing environments that can stimulate that.


On the other side, if you have a genetic predisposition for say, liver disease.


Speaker 5

Right.


Speaker 4

The phenotypic expression of that genetic disposition is obviously liver disease.


But we can impact how extreme that might be. Or if it develops, or how it develops through diet, not drinking, certain things exacerbated.


Speaker 5

Right.


Speaker 4

The impact the probability of that phenotypic expression of that genetic predisposition.


Speaker 5

Yes. All right.


Speaker 4

Now, one of the important questions development that was asked about the development of phenotypic traits.


Concerns phenotypic plasticity. Plasticity, you should recognize as one of those social concepts for development, right?


So how much of our traits are determined by the genotype.


Or how much about are open to influence by the environment.


A trait with low plasticity, such as eye color, the genotype is strongly influential.


And the phenotype develops in highly predictable manners, irrespective of environmental factors.


In contrast, in traits with high plasticity, the genotype exerts less pressure.


So the phenotype is easily influenced by the environment and develops less predictably, as in the case of intellectual skills and abilities.


Canalization is another really important principle related to phenotypic plasticity.


Basically, cannibalization is when a trait is relativity invulnerable with environmental events.


These traits are much more restricted by their genetic makeup, much less open, much less susceptible amenable to change due to variations in the environment.


These are usually traits that have been chased by thousands and thousands and thousands and thousands and millions of years.


And of evolution. And are common and have and maybe most importantly are necessary for all members of the species for survival.


Speaker 5

Right?


Speaker 4

It is sometimes adaptable to not be susceptible to the environment.


There is components of herself, right? Your genetic makeup. Especially if that function is necessary for the survival.


So when we look at the figure on the slide at the top of the plateau is infancy.


And the valleys are all the possible developmental pathways and trajectories that lead to various phenotypic outcomes.


All those forks in the road. There are other ones.


Speaker 5

I could put.


Speaker 4

Arrows. But all the forks in the road where one or more valley is available.


Is high plasticity.


Speaker 5

Right?


Speaker 4

Where the environment will have can play a larger role in determining that phenotypic expression.


More pathways for them to go down, depending on what the environment is that the person is above.


All those low, narrow, deep valleys which follow very confined forces.


These are catalyzed or areas of low plasticity. No one go a long way. And so the environment phase of often less of an influence with these ones.


Language is an example. Walking, forming friendships or others shared by all humans.


Unless something major goes away in development.


People with widely varying experiences hearing language develop it just fine.


People with varying degrees of even intelligence or exposure to language will still develop a form of communication for Their own languages to communicate with each other.


Now, obviously, if you stick with normative developments, as long as you are exposed to language, you will learn language in whatever form.


You're exposed to them in multiple forms. Another one is linked motor development. And that the sequence of development is often invariant.


There are some level of variance, but not the same as other type boundaries.


Usually things are floating over, spinning up the bottle, creeping and so on.


There is is a kind of set pattern that we often see that we don't see it necessarily in the exact order.


We often still see them, right? They learn all of the same skills. So on the one hand, low plasticity analyzation ensures the development of certain essential traits to develop in a normal trajectory.


They're not easy diverted by environmental variations.


You can speed some of those up, you can slow them down.


But usually as long as there is exposure, they will develop.


On the other hand, the high plasticity of subversion traits ensures that each individual is able to adapt to changes in environment.


We need that ability to adapt. So again, this is hitting the plasticity, that idea, that central concept of plasticity.


And also some level of continuity and discontinuity.


Because even with canalization, we often see is kind of an example of continued continuity, which we see gradual developments, questions about.


So we've covered some important principles. We're now going to look at how we study gene environment interactions.


Now, one large branch of developmental psychology that attempt to study this area is called behavioral genetics or behavior genetics.


This is a field of development in which researchers try to understand how genetic and environmental factors combine to produce individual differences in behavior.


So a typical behavior genetics question would be, are the differences in IP IQ of Canadians more due to genetic factors that may carrot from our parents or to the environment that we live in?


Now, an important point to notice is that behavior genetics is not the study of genes.


It's not molecular biology of genetics, okay? Rather, in these studies, researchers attempt to infer the input gene are specific to behavior or traits and determine how much variation in a population in that specific trait is due to genetic variation.


So no new genes are discovered from a major genetic cycle, okay?


Researchers in new genetics study distributions of circular behavior pattern traits, etc.


Among relatives who differ in degree of genetic closeness.


So when we look at herbal, this is the degree to which variation in a particular trait, iq, shyness, schizophrenia among different individuals is due to genetic differences among those individuals.


The more closely people are related, the more genes they have in common.


Parents and children have a 50% overlap with the genetic dominance and so do siblings.


On average, aunts and uncles have about a 25% overlap with nieces and nephews and some who bear parents with their grandchildren.


Thus, if genes are implicated in the physical traits or behavior pattern, people who are more close, closely related should be more likely to share that pattern.


You probably need more than a parent or brother, than a sister or a cousin.


They probably look very much, very little like a shaker.


So there's a photographer who spent their life going around the world photo maybe like double dangers.


The friend would be all from doppelganger. So biology lies to you. I'm lying to you right now. There's somebody out there that looks exactly genetics in like in our religion.


There is also in the world around examples.


Speaker 5

I.


Speaker 4

You know what? The more that I see this person's photographs, I believe that, well, there's other things.


And again, there's only depending on what you believe.


We all originate from not like the same place in the world.


And we all.


Speaker 5

Right.


Speaker 4

And so we all share in that genetic makeup something.


Who's to say that the probability of mixing enough similar genes and then getting enough of that kind of plasticity to create similar people.


Sure, I really played a lotto on that, but I don't play a lotto.


So is it possible that Doppler Gangers also have a 25 genetic overlap like you would with the aunt or.


I wouldn't say that it's 25. I just think because things are probabilistic in here.


Speaker 5

Right.


Speaker 4

That there's, you know, it's likely that there was enough similarities that we were looking for, if that makes sense.


Like some things I'm also going to say is like you think they look like each other and so you see them looking like each other, but there are still differences.


If you were to look at the gender like again, most of us here share same genetic.


We just pair different.


Speaker 5

Right.


Speaker 4

So there's still overlap even if you don't look alike.


So it could be the same overlapping.


Speaker 6

Like a singular tribe move through different. Oh, Prometheus. Yeah, yeah, sorry.


Speaker 4

I'm an alien. Span of aliens and predators right there to where I just went.


That's where my mind went on Monday morning.


Speaker 5

Okay.


Speaker 4

So again the idea close with your lady. You should share it should look more like that your traits should be more similar than as you get genetically farther apart from people.


Speaker 5

Right.


Speaker 4

Another fun fact.


Speaker 5

I.


Speaker 4

This is a personal example.


Speaker 5

Okay.


Speaker 4

Have two sisters and two brothers. None are twins. And only one shares the same bond with me. And please share the same mom and dad. So I have two sisters, two brothers. I only share one pair. One of them not staff. Basically one half in three. No, three possibilities with each other, but one of them.


So there's four siblings. So three full siblings.


Speaker 5

These three.


Speaker 4

I love doing this.


Speaker 5

I love doing this.


Speaker 4

So these three share the same mom and dad, but they are my siblings.


This one shares the same mom with me. They are my. My sibling.


Speaker 6

So then the other one shares the same to add.


Speaker 5

No.


Speaker 4

Well, these three share. This one and me do not share. I do not share a father with anyone.


Speaker 6

Oh, okay.


Speaker 4

My mom and my aunt are identical. Tears.


Speaker 6

I think I remember.


Speaker 4

You have a twin cousin. My mom and my aunt are identical twins.


Speaker 5

Right.


Speaker 4

And so technically, because they have the same genetic material, all five of their children have half the same genetic material from them.


Speaker 5

Right.


Speaker 4

My sister and I are technically half siblings. We do not have the same father, but my three cousins, technically, my genetic siblings have the same father.


And I look more like my female cousin than I do my sister.


Still confused. So I acted my brother. My oldest cousin meets my brother cousin.


Speaker 5

Right.


Speaker 4

He came to live with us when he was younger, so. Exactly. I lived with him since I was about 18 months old. So, like, I grew up with him as my brother.


Speaker 5

Right.


Speaker 4

But his two siblings were from a different household, and so they're my cousins until I got old enough to figure out what was going on together.


Speaker 6

Well, I was saying, if the only relation is the. The twin sisters as the two parents, why would you end up looking more like your cousins?


Speaker 4

Okay. It's a mom. You look. It's through the mom. Like you are our maternal. Because we look like our grandmother. Okay. I never considered it that way.


Speaker 5

No.


Speaker 4

But yeah, because I definitely got to have. But also means if there's ever, like, bone marrow issues, we have many of us that we might be able to.


No Bible match.


Speaker 5

Right.


Speaker 4

Closer to you.


Speaker 5

So.


Speaker 4

But yeah, so there's. Your professor is weird.


Speaker 5

Extra weird.


Speaker 4

As a question, you can see.


Speaker 5

If.


Speaker 4

They can figure out no, but they can only ask yes or no questions.


Always do this in yes or no.


Speaker 5

Okay.


Speaker 4

So moving into. Okay, so when we talk about variability, we use the variability statistic.


And this varies from 0 to 1. And this is just an index of the relative contributions of the differences in genes or the differences in environment which place more independent traits.


So sometimes researchers will say things like that trait is 51%.


Preliminary, that just means that the heritability estimate is 0.511%.


A high heritability estimate is taken to mean that the variation in the trade gain exams is due in large burdens to genetic influences, not environmental.


So higher, close to one genes are playing a larger role in determining the phenotypic expression of that gene.


A lower one means that the environment is likely to play a larger role in the phenotypic expression.


Now we estimate using different types of what are called kinships studies, which use naturally occurring conditions provided by kin relationships.


Speaker 5

Right.


Speaker 4

To estimate genetic and environmental contributions to phenotypic traits.


So in a kinship study, researchers compared individuals who differ in degree of genetic relatedness closeness on a trait of interest.


Speaker 5

Right.


Speaker 4

If a trait is for people who are more close to genetically related should be more similar on that trait.


The main types of kinship studies are there are family studies, twin studies, and we'll look at adoption studies in a second.


So family studies are exactly what they say. They compare members of the same family and they see how similar or not similar they are traits.


When we look at twin studies, so family study, they would look at your parents, they would look at you and then siblings.


Speaker 5

Right.


Speaker 4

They also look at grandparents and they look at your family history there.


Speaker 5

Right.


Speaker 4

That makes sense. You just go down the family tree across. When we look at twin studies, they here they look at monopsychology, same egg, identical twins.


They can look at dizygotic twins, which comes from two different eggs that are fertilized.


Speaker 5

Right.


Speaker 4

These are fraternal twins. And what they try to do is they try to do twins with the same sex because you want to control gender differences.


But they can also look at opposite sex paternal, those two.


It's a lot like this. You can do many iterations of twin studies. But ideally what we're looking at is if one zygotic twins show greater similarity on some trait or some behavior than the dizygotic twins, we tend to say that there's a larger genetic basis.


So after higher her estimate is often given. Any questions for those? So with adoption studies, what we are looking at here is we look at when children are separated from their biological parents at an early age and reared by adopted parents, they do provide special opportunities for sorting out some of that nature nurture question.


Basically, psychologists look for relative similarities between children and their adoptive versus their biological parents.


Speaker 5

Right.


Speaker 4

But children who are reared by adoptive parents are nonetheless more similar on some trait that we're measuring to their biological parents.


That's a powerful argument for genetics.


Speaker 5

Right.


Speaker 4

In that phenotypic expression of that trait. You can also compare genetically unrelated children raised together and look for similar patterns in gene expression.


You find Similar patterns in genes in that phenotypic expression in biologically unrelated traits.


That's an argument for environmental factors having a larger impact.


Again, we are simplifying this data. Now. Adoption studies do have some.


Speaker 5

Well, any.


Speaker 4

All of these separate indications. Even though we do between twin studies. There's always the argument that identical twins because they share at least a more similar behavioral environment.


And oftentimes depending on how they are treated.


No identical twins were they actually treated as individuals growing up.


Can we say where they're treated as almost the same person?


Pretty much the same person. So there are often times depending against where family units that environmental component of how the family treats an identical twin may actually provide more similar environmental like shared environments.


So while we say that often we look at that, you know, the same twins are showing more similarity.


Genetics still can't rule out environments. Because for some of us they are treated very similarly.


Literally not even before birth.


Speaker 5

Right.


Speaker 4

You can still also argue though that in the road there are often differences between the environments that one between experiences versus the other.


And then people first all of these complain again, still gets complicated.


Even with adoption settings would be because often times the if it's a reputable adoption agency, it will look for potentially similar depending like cultural or social environments to the biological parents.


Not always happening. So again if there's similarities again you get that shared environment or the genetic factors.


So even these studies it's not right. This is why it's called an estimate. Many Neptunes that there's lots of different issues.


Anyways, the basic is we look at people we're genetically related and variations of that and see where they fall.


Speaker 5

Okay.


Speaker 4

And the environments they grow in.


Speaker 5

Yes.


Speaker 4

So based on hundreds if not thousands of studies studies variability estimates have been obtained for many human traits.


As genetic similarity increases, similarity in terms of each one of these also increases and many many more.


But there are a few things that we also need to keep in mind about estimates of peratility for the same trait.


Not the same across populations. IQ in urban areas is different than in suburban areas.


So there are environmental conditions even with highly pervertible traits.


And even though traits may be highly vertical. Again, it doesn't mean that the environment does not vertical.


So again is that interaction. But at any given time, depending on the trait, one plays more of a factor maybe in so genetics possibility.


The low and higher possibility the environment can help maximize that possibility.


Your genetic code may say you can never be bigger than single.


Speaker 5

4.


Speaker 4

The environment can help you try to maximize that.


Speaker 5

Okay.


Speaker 4

Now, unless something is wrong you're stuck. That's the maximum. Again, does that make sense?


Speaker 5

Yeah. And also.


Speaker 4

There'S a general problem with heritability studies to keep in mind.


They are still valuable, but they assume that genetics and environmental factors make separate contributions to the development of that much different traits.


But they don't technically interact. So a lot of times they'll say the genetic heritability of height is, you know, 60, 60 to 80% of height is available.


And then it's this other. Okay, well, the other kind of 20 to 40% must be environmental.


So it seems to say that this much is this, this much is that.


That's not the case.


Speaker 5

Right.


Speaker 4

They do interact. They don't actually each other that way.


Speaker 5

Right.


Speaker 4

And this is because, you know, this is kind of like an added model.


It's developed add to the environmental effects to create.


So a lot of herability estimates and studies use this additive model instead of that interactive model.


Speaker 5

Right.


Speaker 4

What this means is that the effect of the same environment will be different based on the individual phenotype, where the effect of the CDO rate may express itself differently based on what environment.


There's nothing to add to this. It's just summing some of the stuff that we went through.


And so I'm going to do this each and every week for you guys.


So I do suggest you take a few minutes now to do your brain dump.


And then when you are done what you learned today, either onto a blank piece of paper or slide or somewhere, feel free to go.


Class 3 - Prenatal Development

Seeks to explain the phases of growth

Prenatal Phase

Development that occurs between conception and birth

Begins at the formation of zygote when sperm penetrates the ovum

Takes 266 days beginning with fertilization

200 billion cells

Three Trimesters

Germinal period / Zygote period

Conception

Implantation

Lasts 8-14 days

Period of embryo

3rd week to 8th week

Formation of major organs

Sexual differentiation

Period of fetus

Week 9 / month 3 until birth

Functioning organs

Grows in weight and length

The term that is used to describe the baby to be

Trimesters are looking at the symptoms of the female while stages of prenatal development look at

The germinal period

If the zygotes gonna splits its gonna split now

24hrs after fertilization the cells meiotically divide

Continues to divide every 12hrs

Divisions are called cleavage

Within 36hrs its 32 cells

Takes 3-4 days to reach uterus

When reaches uterus it hangs around for 3-4 days

Implantation takes another week

Blastocysts Fluid filled ball of cells

Blastocysts will develop into embryo

60-100 cells in 4 days

Transition to embryonic period

Embryoblast (inner blastocysts) will become embyro aka fetus

Trophoblst (outer blastocysts) turns into 4 membranes

Blastocycst cavity keeps the inner and outer separate also produces nourishments

Amnion (holds amniotic fluid water tight sac regulates temptaure)

Chorion (lining placenta attached to uterine tissues helps provide respiration and eliminates metabolic waste)

Umbilici cords (tube containing blood vessels connecting embryo to placenta)

Placenta (develops from embryo and mom filters blood)

Newly fertilized eggs survive with little to no nourishment from mom they survive off urine lining and its own yolk

Cell differentiation qualitatively different cells

Vagina is acidic so sperm must escape or die

In healthy man 60% of sperm I bless than perfect (2 tailed)

Success is controlled by woman’s body not sperm

1st obstacle is cervix but during ovulation mucus is watery that will guide sperm thru

After entering sperm still 2 day swim away

Only altered sperm can penetrate egg

The egg is chaperoned by picky support cells that decide to let some serm through

Egg is encased in zone thick protein cell

To fertilize eg sperm must break thru zone

Proteins protruding from sperms cap must match the caps coming from egg and if they match sperm egg can push thru because of hole formed by dissolving enzymes

Now the membranes of the two cells fuse

Eg takes sperm inside

More than 50% of fertilized eggs fail to develop

Egg orders zona to lock every other sperm out

Single sperm once inside releases 23 chromosomes in the egg

The chromosomes approach each other and cell divides

Fertilized egg is now moving down fallopian tube

If cells fall apart/splif twins are made but usually they stay together

Blastocysts must break out of zona and find food by releasing enzymes that eats up zona

Now that blastocyst is out of its coating white blood cells try to devour and protect it but in self defence the ball of cells releases enzymes to trick moms immune system

Two weeks after conception when blastocyst is the zize of a poppy seed GASTRULATION occurs

Gastrulation happens deep within uterine lining

2bubbles and in the middle is a thin layer of cells that will become a baby

At beginning of gastrolation cells form 3 layers

Lower layer- lungs liver digestive lining

Middle layer heart muscle bones blood

Top layer nervous system skin brain hair

The brain is the first thing to be developed

Heart begins beating , back bone forms as embryo lengthens

4.5 weeks afterfertilization an eye a large brain and

Period of the embryo

3rd - 8th week around 6 weeks

Cell differentiation intensifies

Endoderm inner - lungs urinary tract

Ectoderm outer - surface parts ears nose eyes sensory receptors nails hair forms into neural tube for brain and spinal cord

Mesoderm middle layer developed later circulatory system bones muscles

30 days after conception is 30x larger

After 2 months organs are in place but not functioning

Amniotic sac maintains temperature

Umbilical cord has 2 arteries one vein connects baby to placenta

Placenta permits embryo to exchange nutrince and oxygen through villi (difusion what can pass through)

Large molecules : maternal waste harsh

Small molecules can pass: water salt oxygen

Principals of growth

Cephalocaudal principal head to toe Head develops before the rest of the bod

Proximodistal principal inner part of the body developes and From centre out

Within the embryonic period u go from nothing to something

Week 3

- 2mm long

Cell specialization

Neurotube (forms from ectoderm) takes shape of spinal cord

Major areas of brain develop

Heart forms and is beating by end of the third week and never stops

By day 28 the heart has pumped over a million times

Week 4

6.35mm 10000x zygote size

Leg and arm buds are visible

Digestive system starts to take form

Major veins and arteries

Vertebrae are present

Nerves begin to take primitive form

Week 5

Lungs are forming

Brachial buds

Umbilical cord

Hand plates

Pre muscle masses in head and limbs

Week 6

Big bobble head (first and grows fast)

Lower jaw bone meeting and fusing

Upper jaw present

Some ears are developing

Webbing of fingers and toes

Deformaties may happen here so Cleft pallet developed here

Upper pallet begins to form

Week7

Muscles r differentiating

Eyelids take shape

Stomach takes shape and position

Neck and face are forming

Genetic sexual differentiation developed

Gonadal ridges (SRY critical period)

Week 8

Fetus can move

Response to mouth stimuli

Round body

Distinctive neck

Gut growth which is why body so fat

External middle ad inner ears

Limbs are elongatied and separated

2cm long 30 grams too small to feel if baby is moving

Period of the fetus

Week 9

Rapid growth & refnement

All tissues and organs exist

Skeleton begins to harden and turn into skeleton

Refinement of organ systems

Increases from 4-51cm and 30g - 3.6kg

20inches in length and 7.5lbs at birth

Fetus becomes more responsive

Influenced by environment inside and outside (maternal nutrition and illness)

Can sense motion light and sound

Behaviour becomes regular and mom can feel when fetus is active

External genetailia (u can differentiate sex)

Week 11

Urine is created and goes to amniotic fluid that the baby stays in

Week 12

Nose chin arms and lower limbs all distinguishable

Visual sexual characteristics very distinguishable

Fetus stretching kicking (can’t be felt)

Week 13

Vocal cords are forming

Week 14

They can taste proteins anino acids

Growth is in bottom

Arm and leg movement

The quickening is feeling the fluttering movements

Week 15

Fetus exhibits all movement seen at birth

Breathing like movements with chest and lungs fetus is sucking in and swallowing amniotic fluid and spits it out so it is practicing eating and breathing

The head is 1/4th of the fetus’ length

Week 18

Myelination

Neurons are connecting with each other

Fingerprints are set

Week 19/20

30cm long weighing close to 1lbs

Toenails/fingernails are forming

Middle ear is functioning controlling sense and balance

Fetus can sense movement in mother and can reorientate itself to float how it wants to

Most nerve cells are formed

Fetal movement is intents

Weeks 22-28

Fetus can survive outside uterus

If fetus is born medical intervention may be needed body is not operating efficiently (incubators)

35cm long and gained some weight

Eyes and eyelids are formed

Lanugo (hair) grows

Vernix is protecting the body and lanugo helps it

Fetus is opening and closing eyes

Sucking thumb grasping reflex is practice for survival

Waking up and going to sleep

Sound level in uterus is 75db

Fetus might sit head down

7th month 31week (third trimester)

Fat is forming

40cm long 1.5-2kilos

If baby is born with supportive medical intervention baby can survive at a 90% success rate

8 Month week 32

Insulation layer of fat to regulate body temperature

Fetus too big so there is a decrease in movement

Weighs 3.2-3.4 kilos

45-50cm in length

Many brain folds are present enabling brain cells

Brain gets wrinklier and wrinklier

Responds to loud sounds

Recognizes stories

Control your emotions, you have some type of relationship with people.


I'm not looking for the basics here. This is a time for you to explore, learn, relive your life.


Right? So pictures, symbols, quotes, things that you may have to ask family members, as much as you can go through your own history, whatever you have access to, to kind of give me a visual timeline, right?


It literally will be visual. So you can do this if you're creative, you can do this in Canva, you can do this.


I mean, you can do it in PowerPoint, you can do it however you want.


If you are a crafty person and you want to do it on a piece of Bristol board and draw your pictures and do your things that way, then you can send in just a photo of that, right?


Or yes, that is the first part is this kind of action timeline in which you're giving at each one of those kind of four stages, like those three milestones, the biological, social and psychological stuff.


It's all in the. In the instructions. The second component is a video of you explaining this, of going through, telling me what these major milestones are, why they're significant to you as who you are now or who you were then.


And also, this is where I'm going to make you tie in the theories.


So in the video, you will be tying in whatever theory you want to use.


The one I'm giving the instructions is Ericsson's, right, the psychosocial theory.


But we're going to go through. We're going to start Piaget today. We're going to do a bunch of different ones as we go through the course.


And you don't have to. You have to do two of them, but you can do more. So if you feel like some of them explain you better at some points, but others explain you better at other points, you can switch between the periods, that's fine.


Okay. So it may be easier for some of you to break that out as your own kind of like storyboard, right?


So be handing that video. And the video is anywhere from about 8 to 10 minutes of talking about, how do you feel already?


And I understand everybody brings with that a different type of childhood and past.


So you are to do this within the realm of what you are able to do and what you are comfortable sharing.


Okay. I'm not supposed to ask you to bury your soul in every given little detail, but again, I don't want this to be generic.


I learned to walk at 12 months. What do you do? Okay, is that significant? Why is that significant? Did you have hip Dysplasia as a child, and you were told you weren't going to walk until you were two because you were the cast.


That is more of a personal, triumphant aspect. Do you see what I'm saying? Right. If you got teeth early, that's terrifying because anybody ever seen some of the dental X rays of children's mouths right out of a hormone?


So that is what I'm looking for. So in that first part, you are going to get creative.


This is a creative assignment. This is a personalized assignment. Okay, Any questions on your. This is also why I wanted. I hoped to get it out last week, but I think we're still within enough time that you guys can start doing this as we go through the course, because at each one of the stages, we're covering it in class.


So as you're going through class, as you're listening to the theories, jot down notes for your assignment.


Oh, I remember when this happened. Right. It might be harder in, say, the infancy stage. Who's in polyphenia, depending on how good your memory is.


Mine is not. I think my earliest is from, like, when I was six. So you might need some help with some of the earlier years.


So go back if you can, look up pictures, find those pictures, relive the different hairstyles.


So you can start doing it now and start kind of trying to pick out those components you want to put on the visual representation.


Obviously, for those ones in the video component, you'll be describing them and why they're important, but in the visual, you can literally represent them if you want, or you can symbolically represent them.


I was an AAC teen, so I used to think. I used to fancy myself a poet and an artist. It was adorable. I was not there. Right. But I still have some of this stuff because I'm also pack rat and I like to keep every.


I have my all of my undergrad notes. Why? Why? Because my parents have a big garage and I'm under there.


And then the mic I don't have anymore because the mice, they had.


But I did with a lot of stuff. Right. And so see what you have. Go back through. This is going to make you uncomfortable, which I'm okay with.


Sit with it. Look at it. Because everything you went through and everything you're going through now is who you are.


Okay. Helped you get to here. I put a positive spin on everything, and I know that I'm unstable, but we all have things that we hope and wish we hadn't gone through potentially to get.


To get us here. So what's got you here? Obviously we're doing this within the realm of development in psychology.


So we're looking at those biological milestones, the psychological milestones, the social milestones, the cognitive milestones.


I think it's bio cognitive, psychosocial or social emotional.


It's in there. All right, as we go through the course, if you have questions, if you want to talk to me or discuss about some of your ideas, I'm very inclusive.


Any questions about before we move forward? Yes, there will be. I haven't finalized the proper, but there will be a creativity.


Now, I don't think we're all going to be an art student, which is fine, but I am looking for you guys to give me more than a straight line.


Are we good there? Okay, so for today's topic, there's actually three components to today's lecture.


And this is because we can't talk about perceptions and order development without talking about cognitive development in infancy.


And we can't talk about cognitive development without talking about brain development.


And so these three kind of sub modules of lectures all fit together.


I'm going to go through as much as I can of these three.


We're just going to go. Whatever I don't end up getting to, it will be recorded and posted because I'm also partway through recording social development for agencies.


As I promised you guys, I want you to have everything for your midterm.


I'm aiming by tomorrow because the TA is going to be giving in class midterm review next week.


I do believe she's not starting at 8. I believe she's going to start a little bit later and I've just asked her when she picked her time.


Post it. So everybody knows that if it makes a difference, you can have that extra half hour hour at home.


Right? I do suggest that you come to the review because it is live during class, it is not being recorded and I will not be giving any other kind of review on the material.


So if you are not in class, you'll give the okay. Your midterm is on the day you return from reading.


So October 20th, it probably is going to start at 8:10 or 8:15.


So I know that can be hard for public transit, but if you're late on that day, just get here.


I do usually make people stay for the first hour, especially for an class because I understand that some days your 401 is working against you.


Public transit is working against you. Okay, so just get here. I can't extend the time, but you will at least have whatever time it is before that.


Hours. So once I let them fill. No, I can't. I'll post more about the actual breakdown of the midterm once I finalize it.


Generally, you're going to have multiple choice questions and then you're going to have a section of short answers for each kind of complicated area.


We might have short answers on prenatal and multiple chart questions in each of the short answer sections.


And then you'll have choice. You won't have to answer all of them. You'll have to answer one or two in each section depending on how heavy they are in a sense, like how much she grabbed me.


All right, any questions before we get into today's topic?


Yeah, just to confirm the format of the exam. It's a choice of short answer questions. Is there any multiple choice on it or. There'll be multiple choice for sure. So each chapter, so when I'm developing my short answers, I'm looking at my lecture is written.


Okay. When I developing my multiple choice, I'm looking at both.


So the textbook ends the lecture. But again there's overlap. So I generally suggest that students study the lecture first, review your lecture first, then do the chapter reading for the first chapter or two.


Some of the theories and that like Foray and Ericsson and like, like the frameworks that we went through, they're not presented in the textbook like I lectured them.


So it's a little bit out of order, but the material is there.


Okay, so you will see overlap. Most of the stuff you know, especially earlier chapters, there's probably about 70% overlap.


The you'll see what the lecture specifically specific material is.


You'll see what the textbook specific material is.


Now if I'm looking at lectures when I'm doing my short answers, it means I'm not making short answers out of textbook from the textbook specifically.


It's going to be the lecture material. Right. But again if there's overlap, so reviewing both of them, your knowledge.


But it means that generally the textbook only material comes out in local choice because there are topics that I think not cover or I can't cover in as much detail.


So if I didn't cover it in lecture, it's going to show up as potentially as a multiple choice question.


Does that make sense? Any other questions? Again, I will, once I finalize it, I'll share an announcement.


Just reiterating. It's going to cover everything up until infant, social, emotional, relevant because when we come back we're going to move into language and early childhood and As I said, do not leave your studying to Saturday, Sunday at the end of your reading week.


Do yourself a favor, right? People can, because you'll look and you're like, oh, there's six or seven chapters of course material.


And when you open up all of the PowerPoints, you're going to say there's 200 slides worth of PowerPoint or more, right?


And then it will stop. Don't look at this, right? All best intentions have the best intention set as a schedule.


How many of you also have another midterm this week?


We're going to come back, manage your schedule. Take some breaks, but manage your schedule. Learn from us. All right, so we're going to get into the topic. So a lot of the physical changes that we see in the first year of children's life is quite uncast.


You remember what we are in saw in the prenatal period and how much change.


What's even more kind of awe inspiring are the changes that we can't see, the changes involving the brain and the nervous system.


So we know that, well, informal to our baby's brains, their central nervous system, all of that support system are in that kind of rudimentary elementary formation.


Right? And this includes your sensory as well as the neural functions.


At birth, brain contains the vast majority of all of the information transmitting cells it will ever have.


So something around 100 billion neurons were born with.


Right. And the amazing thing is that the brain itself, even though we're born with almost all of the neurons we'll ever have, kind of it's four times larger by adults at five.


Right. And most of that growth in the brain occurs in the first few years after birth.


So this is what we're going to look at in the first part of today's lecture.


I am going to let the textbook do some of the heavy lifting with regards to biological growth.


But I have one slide. So to understand this growth, we need to understand the nerve, the nerve cells that transmit information, the neurons, as well as the different brain structures which the neurons are organized in.


Which the neurons are organized. Okay, so again, basic bio. The brain, the brain is composed of neurons, which are the communication cells in our brain.


And there are other warning cells there as well. We won't be looking out. We're just going to stick to their nose. As I mentioned, mature brain is composed of about 1 billion neurons.


And these neurons then make about a trillion connections with each other.


Right. A piece of brain the size of the brain of Bryce contains about 10,000 nerve cells.


And each of those cells Will make anywhere from 1 to 10,000 connections itself.


Neurons communicate by sending information via these small electrical impulses along its axon, which leave the neuron at the axon terminals.


And neurons also receive information from the axon of other cells in their dendrites.


And that's a chemical process. That's when you talk about neurotransmitters. As the child matures, the axon neurons grow in length, so they get longer.


And the dendrites and the axon terminals proliferate, so they increase in number and the number of projections, Creating these vast interconnected networks with the transmission of complex messages for everything.


You're grateful, ducks, right? It's kind of why it's very hard. Even with all the technology we have to replicate the brain in its neural network because of the number of connections and how they connect, but also how they disconnect from each other too, right?


We'll talk about synapses and stuff. So just briefly looking at the brain, the wrinkled surface of the brain creates outermost layer.


And the most complex system is our cerebral cortex.


It's the processing center for the perception of patterns, the execution of complex motor sequences, planning, decision making, speech.


It's made up of about 10 billion neurons and is divided into our two hemispheres, which are linked by millions of axons.


That's that corpus callosum that links the two hemispheres.


And each cerebral hemisphere is divided into its own four sections or four lobes, right?


Separated by very deep groups. So you've got your occipital lobe, which is specialized in France vision.


It gets input from the eyes and the optic nerve. It contains the primary visual cortex, secondary visual cortex, and it itself outputs to the parietal and temporal lobes.


You have your temporal lobe, and this is specialized for hearing and speech.


It also is involved in vision and memory and emotions.


The auditory cortex is input from the ears and visual input from the occipital lobe.


Do you guys know where your lobes are? I mean, it's on the picture. Your occipital lobe is the one in the back of your head, right?


Your temporal is the one that's. Think just about your ears. Ear, right. The prior kind of goes above that temporal. And then you've got your frontal bone, which is in the front.


Fun fact. I got smacked in the back of the head by a soccer ball in the way.


It might have been some intent. I went up for a header. I don't know if it was taller ahead. And my visual field went completely all chittery.


And then it was like technicolor I don't know how long later.


It's called the concussion. So that was a concussion, but it went with Technicolor.


Have you guys ever seen like a black and white movie?


Go Technicolor. Where they start. And it was pew. So that was fun. And then they just continued like they didn't have compression for the time, but.


So I'll send a little back here. Don't again. So coming back to the, the temporal lobe as I mentioned, so it's with regards to auditory information.


Visual input as well is linked recognition in memory, specifically speech recognition, face recognition, word recognition and memory formation.


You have your prior lobe and this is specialized for spatial perceptions and sense of touch.


So it gets input from multiple senses. Right. So it gets input from the touch to the somatosensory cortex against input vision via the.


It gets obviously has input lobe as well because it's.


It's also involved in our sensory motor control.


So if you have bad eye hand coordination, you can blame your cryola.


It's its fault. It's also involved in eye movements and attention.


When we look at the frontal lobe, this is specialized for control and coordination of kind of all the other cortical areas.


And this is to enable all of our very human complex discipline forms of behavior, thoughts and feelings.


And it's also involved with motor control. So when we look at some of the higher order functions of the frontal lobe, it is the thing that helps you plan, it is the thing that helps you reason, it is the thing that helps you make judgments.


It is a thing that is involved in your impulse control or lack thereof.


Right. It is involved in memory, personality. It's done a very good job. And as I said, it's also involved in motor functions.


Now there are large areas of our brain that aren't pre wired for certain functions.


These are our association areas and they allow for change and growth based on experience.


So they are association areas, allow for that plasticity to do its thing.


Now a few other important parts of the brain. We have the limbic system, which is located deep within the temporal lobe.


It's sometimes referred to as the visceral brain and is related to the survival of the organism and is closely related to motivation, emotion and memory.


It's kind of what controls the four R's flight, fight or fear, feeding and fornication usually just refer to the fighters that.


But there's other acts that go with that. All right, Feeding information. It contains the amygdala, the hippocampus, as well as the Hypothalamus the thalamus, the cornx and the septum.


There's a lot of other structures there. Now the hippocampus itself is very important for the formation of new memories.


If you didn't have it, if it's damaged, you couldn't live the present present.


So depending on when that damage occurs, you would still have your past, assuming you aren't an infant, but you again only be stuck in those old memories from before the damage to the hippocampus.


So there was a case of patient being m in the 1950s at age of 27, part of their temporal lobe and the underlying living system were actually removed on each side.


So the other side couldn't kind of take over through that plasticity.


Right. So it couldn't adapt. And this was due to epilepsy, severe epilepsy. Now it relieved the epileptic symptoms, so I guess it was successful and what it was meant to do.


But it left HM with huge memory impairments because they couldn't encode new information.


So they could still remember the events that had happened before the surgery.


They could still have conversations, they could still read, they could still solve problems.


They could still solve problems and keep new information in mind as long as they were attempting to it.


Because at that point it hasn't gone in, it hasn't been processed into long term storage, it's still in your working memory, you're still able to keep it there.


It's like you repeating a number, right? It's still there. But the minute H.M. love shifted attention, that information was gone.


So even when they asked the patient asked HF to draw a car years later, it was, I think 40s, car, not present today.


And the family had moved right after the operation, which meant HM kept going back to the old house.


This could never remember that they. So he needed a constant companion and reminded what he was doing because again, the minute he shifted attention, he forgot what he was doing.


He could be eating and if something caught his attention, he would forget that he was going to be eating.


Map tricket for cameras and again, a lot when we do see damage, that's what extreme form.


But when we do see damage to this area, it usually results in more problems with what we call episodic memory.


So personal specific events rather than semantics.


So the facts about the world. Younger patients, so even birth, two years, nine years, can still learn to read, go to school, have good vocabulary, but they don't remember learning it, so they just know it.


So they have no memory of how they got these Skills, depending on how old they were when the damage reversed.


We've heard about the amygdala before. I'm assuming most people know about your amygdala.


It's important for emotional responses. There have been studies that show that damage to the amygdala can interfere with memory that is strengthened by emotion.


And there's research that's shown that stimulating the amygdala plays with role in both the display of aggression, so the increase of and the modulation, so the reduction of aggression.


Other kind of key features of the brain and brain function include lateralization and functional interconnectivity.


When we talk about lateralization, this refers to the fact that the two halves of the human brain are not exactly alike.


Each of the hemisphere has functional specializations.


Some functions of neural mechanisms are localized primarily in one of those two hemispheres, one area of the earth.


When we look at the left side, the left hemisphere, this actually gets input from our right side, so it crosses over.


So everything down your right side, except for your eyes, their unique face.


Everything from your right side travels up your nervous system across the corpus callosum into the left hemisphere.


The same is for the right. The left side goes up, crosses over into the right hemisphere, the left hemisphere itself.


It seems that language is primarily localized on the left side of the brain, as well as mathematical abilities and positive emotions.


When we look at the right side, this seems to be more invested in having recognition, including that facial recognition, spatial organization, recognition of melodies and the negative emotions.


So with regards to lateralization, we see that there is what's called inflammation crossover, right?


Meaning again, as I said, the right hemisphere is responsible for the left side of your body and vice versa.


The right to the left, left to the right, square all the way down the bottom.


Your eyes are different, right? Both brain hemispheres control both of your eyes, right?


But one takes charge of one half of your visual field and the other takes charge of the other half of your visual field.


The eyes are phenomenal, but we're not going to go into the eyes when we talk about functional interconnectomy.


So a lot of early research into our brain emphasized or was trying to determine what each individual part section of the brain did, and often in isolation from all of the other components of our brain.


But parts of the brain can't function on their own, right?


This is why we also have a corpus quasum, because there needs to be that communication.


What we know is that different parts of the brain are intricately connected with each other, forming those neural networks.


It's these connections, these networks that make the brain work not each on its own.


Your hippocampus can't make a memory if it's getting no input for your occipital lobe and the temporal lobe and the parietal lobe.


Because our memories have sensory traces, right?


Our memories are based on our experiences. And what are your experiences? All of your sensory information combined into this reconstructed story of what happened.


Right. And so we go progress to the projections in end the.


Into it. I can't take your hippocampus and go, okay, here's your memory.


It's not just going to. And so what we know is that the connections between different parts of the brain is crucial for normative brain functioning.


And it's not true that we only use 10% of our brain.


I don't know the exact percentage. But it's truer that there are smaller percentage of our brain that is specialized in function versus those larger association areas.


Right. And in some of those larger association areas that if a small part of one of your lobes is damaged, they can take over or help with the job of that other area.


Again, it's that plasticity and the fact that the brain can adapt when you develop specialized skills.


Some of that is because the association areas are involved and strengthen those networks.


Any questions so far? Some of this hopefully, is review. All right, now, around the age of 12, a child's brain has the size, folding in weeks and regional specialization of an adult, but it still has a very long weight in terms of function.


So like you saw in the prenatal period, all of that structural components are there, and then function talks.


Right? Now, it used to be thought that the adolescent brain was this kind of black box.


Obviously, with the advent of new technologies, you can actually start to look at live brains.


And we've been able to look at live brains. And it really did launch a new area in analysis science because again, look at a living, growing human brain and not just its structure, but it's also its activity because they knew something happened in adolescence, right?


But again, when we look at the structure, it looks like an adult brain.


But let's be honest, as an adolescent, we're not functioning like an adult and we're not functioning like a child.


Right? Now, what we see now, for example, in the frontal areas, so things the area dealing with executive functioning or even planning, we always start to see this area coming to maturity in function and like structure and function in kind of late adolescence.


Right. And that the brain doesn't begin to resemble that of the Adult properly until about the early 20s now.


Right. And during adolescence, we see a second surge of what called synap, resulting in the thickening of the gray matter.


We'll go into snap. And snapogenesis happens especially prevalent in the frontal area of our brain.


Right. During adolescence. And part of this also the increase in gray matter is we see an increase in neural network connections.


Did I need a video clip? So that's a very mini introduction. What we're going to be looking at now is some of the important developments and processes.


A lot of these happen in the prenatal period. Right? Prenatal period puts building blocks into place for the development of the central nervous system and the brain.


But also we do see that limited neurogenesis happens in parts of the brain into adulthood.


And a little bit later, circuit formation is always happening as long as you're learning new skills.


And my mediation does take a couple of years into childhood to property there.


All right, so we know the beginnings of brain development trace back to the period of the blastocyst.


Right. At roughly about three weeks after conception, the nervous system begins to form from a group of cells which form a flat structure known as that neural plate.


At four weeks, that neural plate folds and starts to form the neural tube, which ultimately becomes the brain and the top of the neural TR tube and your spinal cord from the bottom.


The neural tube forms from the ectoderm, right, that outer layer of the embryoblast.


When the ends of the tube fuse shut, Neurons are produced in one small region of that neural tube.


And production of the neurons begins around six weeks after conception.


And by about 28 weeks, the developing brain has virtually all of the neurons of the low path.


Cells inside the tube form your central nervous system.


Cells outside the tube will form your peripheral nervous system.


And during these weeks, that 6 to 28 week period, neurons are forming at an incredible rate of more than 4,000 per second.


Remember, at 100 billion of these, so quite a lot of them.


Here you can see how the neural tube gives rise to the entire nervous system, including the brain and spinal cord.


So from the neuron manufacturing site in the neural neural tube, neurons migrate right to their final positions in the brain.


And the brain itself is built in stages, beginning with its innermost layers.


So it's kind of like a reverse onion, right? Hit the middle part of the onion first, and then it builds the next, and then it builds the next, and then it builds the next until we get the brain as we know it.


Now, neurons in the deepest layer. Again, our position first followed by the Narazi second layer, so on and so on.


So this layering process continues until all six layers of the mature brain are in place, which occurs about seven months after conception.


So it's again around that third to fourth week that the cells are starting to divide very quickly.


At its peak, neurogenesis is happening. About 250,000 new cells being born every minute.


So again, 4,000 per second. So that is very impressive. Neurogenesis itself refers to the growth and development of neurons.


All right, the process, if you think about it, neurogenesis, gen neuri neurons, okay.


This process is most active while the baby is developing in the womb and is responsible for the production of the brain, of the brain's neurons.


This is the proliferation, this is the production of neurons through cell division.


What type of cell division? That's. And nerves are being born as soon as that neural tube starts to form, and it's almost complete by about 18 weeks after conception into that and then into the form of other supporting cells called Gl are being born at the same time.


So we have supporting cells that are also kind of coming into place here at all.


Now the question is, when do neurons stop being born?


When does neurogenesis end? Like I said, we're born with almost all 100 billion neurons that we'll ever have.


It was previously believed that neurons were not produced after birth.


Recent discoveries have shown that most neurons is completed by about the second postnatal year, so about two years of age.


But postnatal neurogenesis continues in at least into middle age in certain regions of the brain.


A lot of that research was done with animal models, and it wasn't until the late 1990s that there was proof that human neurogenesis actually continued after birth.


But again, it's in very specific areas. So the olfactory bowl is one. The hippocampus, which is involved in your memory, which you continue to form for your entire life, also does see some neurogenesis later on.


And they are in the hypocrisy campus is specifically the den Tate gyrus, which is final and allowed grades differentiated in similar memories.


So it's what helps you remember where you put your keys today and not yesterday.


Do you mind saying the name of that again? Dentate gyrus. There's some recent research that shows that the inventula may also have layer neurogenesis, parts of it, and potentially the prefrontal cortex.


But again, the research is. So essentially what they think at this point is that some of this adult neurogenesis may help us Remember more things and if used, but it's still not well understood.


Now, what causes post birth of neurons? Some of the suggested reasons that we see neurogenesis after birth is the result of environmental enrichment, such as expanded learning opportunities.


Decreases are often what you would think. Stress, other negative experiences, right. Exposure to cortisol, psychological stress. All of these can actually the growth of newly born nerve cells.


Now, when nerve cells are not born, they do not. Our brains do not go through neurogenesis when components are very damaged.


So once that structure really is in place, right.


If part of your brain is damaged, it doesn't grow new neurons.


Where the customer comes in is projections, hopefully will come from the association areas and those areas will change over to help compensate for the damaged areas if possible.


Some of them is age dependent because our grains become a little less plastic as we age and some areas are just less plastic.


Any questions so far? So we got early developments in brain structures, the liberation of neurons.


Now what? Well, now we're going to look at circuit formation.


Acids and dendrites begin spreading. By about B15 in the Phoenix, these processes begin forming connections called syn acids.


Syn acids allow neurons to communicate between each other.


In the months after birth, the brain grows rapidly, axons and dendrites for longer.


Right. Like a maturing tree. Those dendrites are perspiring limbs, new branches, things like that.


And it's a combination of the sending neuron and the receiving neuron that represents one to one, the simplest kind of form of neural network.


More complex networks are formed as multiple dendrites and axons connect with each other.


Right. The inputs and the outputs, right. Kind of connect with each other, the different parts of the brain.


Many networks are established initially during the second half of gestation of that prenatal period.


Although after birth they may change considerably in size and in organization as a consequence of biological growth and experience.


So just basic brain maturation as well as experience that happens after birth.


I'm hoping that the diagram is enough for you guys to identify what the axon is, what the dendrites are.


Now, the neurons are not actually connected to each other.


Remember, like the fetus and the mother's link, bloods don't touch.


Neither do neurons. Okay? Between the axon terminals of one cell, the dendrites of another cell is a small space known as the synapse.


It's here that in the synapse of the message from one or the alpha levels of one neuron are transmitted to the dendrites of another.


This is the chemical transmission of a Message, Right.


These are the neurotransmitters. Three or four different ways that they work. We're not going to go through them for right now. So this semi neuron secretes that neurotransmitter into the synapse that carries the electrical impulse.


It carries that chemical message across and it essentially tells the receiving neuron to fire or not.


Pretty simple word terms, okay. And it intelligent fire. That's where you get the electrical one, the electrical message going down the axon of that neuron to the next one.


And then it would release its chemical. Now this is a very simple one to one, but like I said, neurons can make tens of thousands of connects.


One connection to 10,000 connections. Connections. So it's sending messages to all of its connections.


Depending on which way those connections are going, it may be sending a different message, it may be telling, you know, it might initiate, put into action a different potential on the other end or wherever it's being projected into.


Are we good there? Now each neuron forms synapses with like a 7,000 mothers, resulting in trillions of connections.


So as the number of dendrites increases, so does the number of synapses.


Synapsogenesis, generation of synapses, right, Is the process of synapse formation and is the most rapid.


During the prenatal periods. And that early postnatal period, there is a massive overproduction of synapses.


Synapsogenesis, go crazy, right? We have many more synapses than we will actually ever use.


And this includes excess connections between different parts of the brain.


Neurons in the auditory cortex are linked with the visual, linked with the taste, linked with the smell.


The peak number of synapses occurs at different times across different brain regions.


For example, at birth, the circuitry of the cerebral cortex is less mature than that of the spinal cord and the brain stem, right?


So the cerebral cortex has fewer dendritic branches, less myelination.


It's poorly connected to the lower lying parts of the nervous system that receive stimulation from the environment.


And it's this synaptogenesis that explains the increase in the fetal and infancy gray matter.


So when we talk about gray versus white matter, gray matter is about the synapses, the networks, the synapse genesis.


Right. Now, synapse overproduction seems to be largely under genetic control.


And the rate of synaptic production depends, again as I said, on the area of the.


So synaptic reduction is completed much earlier for the visual cortex, right?


So, proposednatally, we see a massive surge in the occipital and the visual cortex at about 2 and a half to 4 months postnatal in comparison to what we see in the front.


We see masses nephrogenous attack happening in the motor related areas at around 6 months of age.


And that prefrontal sees its surge later on, about seven to nine months, when we start to see the infant be able to regulate their behavior and to engage in voluntary behavior, not just reflexes.


So up until a kind of that time, they have the ability to produce movements, but it's not always voluntary.


And if you think back to the principles on the table that I put in the postnatal lecture, I think it might be slide 35.


This is just going along with that idea that development happens unevenly.


Some areas mature more quickly, develop quickly.


So how do we then get down to the adult level of synapses that we need?


Well, soon after the baby's first birthday, synapses begin to disappear gradually.


And this is a phenomenon known as synaptic pruning.


Fruit, new trees, new bushes, Right. Experience is what determines which synapses will never die.


This is a use it or use it phenomenon. So getting an infancy, continuing into adolescent, the brain goes through its own version of downsizing, essentially weeding out unnecessary connections between neurons.


The timing of the pruning also varies across different brain regions.


Elimination of the synapses in the visual cortex begins mid end of the first year and continues until about age 10.


Synapse elimination in the frontal area is very slow.


During peak pruning periods, as many as 100,000 synapses will be eliminated for seconds.


And there is evidence that there are two waves of synaptogenesis and synaptic breeding in human development.


Obviously, the first happens in the prenatal and the early years postnatal, and the second happens in adolescence.


And a lot of what we see in adolescence is very similar to what we see in that first year of postnatal development with regards to synaptogenesis as well as synaptic brain.


And so around the age of 11 to 12, we start to see a dramatic increase in gray matter of the brain.


Again, gray nada is made up of the neural cell bodies, the axons, the dendrites, and all those support cells.


Any questions with that? Well, what is the white matter made of? Question, what is the white matter? I changed the slide. Was the answer my answer? Right? So the term myelination refers to the process by which axons are coded in myelin, right?


Starting about the fourth month of the prenatal developmental period, continuing into infancy, into childhood, and leading into adolescence.


Many neurons will be tightly wrapped in a white, fatty mining sheath.


And this giving them the appearance of looking like a string of sausages.


All of them together, right? The high atoms of the mag insulates the neuron from the electrically charged atoms in the fluid that keeps the nervous system in this way, because of the electrical current that is moving down the axon, right.


Is minimized and messages are conducted in four.


So again, this is white matter. This is the white matter we were talking about, the brain.


And it's the second reason for that increase in brain volume.


So myelin insulates absence of an electrical signal to travel faster and more efficiently between neurons.


It allows the electrical conduction to skip from node to node to node to node.


And the average speed is about 3, 300 kilometers per hour that those signals are being sent through the brain.


Myelin is not complete at birth. Myelination is part of the natural biological maturation process that leads to changes in our abilities, changes in our abilities to be a webtail, to voluntarily control some of our neighbors, to rolling over, to crawling, to walking, to running, to thinking effectively and efficiently and quickly.


Incomplete myelination accounts for some of the helplessness of our neurons.


And again, what we saw before, we see here. Different brain regions get myelinated at different periods of time, with simpler areas becoming myelinated first.


So some of the sensory motor, brain stem areas, those early parts of the brain that are necessary for human survival, they get violated first because they need to be able to coordinate what they're doing so that our heart beats and our lungs breathe and our body does what it needs to do.


And this also means that some of the cortexes, especially the frontal regions, come later.


So again, not all neurons are covered in mining at birth.


There is a clear link between what an infant can do and the migre nation in that area.


So at birth, again, parts of the brain involved in the heartbeat, sleeping, arousal, and reflex activity are fairly well myelinated and functional.


The myelination of the prefrontal matter of the brain continues into the second decade of life, into your 20s, into your early adulthood.


And this is where we see the connection with our advances in working memory, language ability, executive functioning.


And there are some areas where myelination continues until the middle age.


Any questions about. So looking at the image bluer, the image means it's more mature, so there's more of that.


Gray matter has been replaced by white matter. Synaptogenesis happened, synaptic drilling has happened, and myelomation has happened.


So again, MRI technology really does now reveal substantial growth in brain volume during the early years of childhood.


And much of this growth is the consequence of that rapidly increasing brain matter of synaptogenesis.


White matter, Miguel also increases roughly during infancy, then more gradually through childhood and into adolescence, decreases in the amount of gray matter reflect again, that process of synaptic pruning in which synapses that are not used, atrophin, die off.


If you use those synapses, they strengthen and they proliferate and they are myelinated because the brain goes, we need these connections, we are using these connections.


And again, the basic parts, the parts of our brain associated with basic functions mature earlier than areas responsible for our hybrid functions.


Any questions about that? Now, looking at the timing of grain development again differs depending on the grain region we're looking at.


And this is because experience affects the final product, it seems because of evolutionary comedy.


We can't just have our brain full pre wired, right?


If you can be molded or changed by experience, this means that a lot less information needs to be permitted to dip them into your genes.


There are parts of the brain that are not completely plastic that are analyzed, right?


But all brains will have a similar structure, similar mapping the functions onto those structures.


So there are certain processes of brain development that appear very early, with relevant synapses in place at work.


The traditional cortex being one of those. And about half of all genes encode things related to the nervous system, but only enough to specify a small number of neurons and connections to put that basic foundation in place, right?


And this is also why we have plasticity, or it points to the idea of plasticity.


This is a good thing, because a child who may experience a head injury may have developmental problem as a result or a delay as a result of that head injury due to branch plasticity, they can feel they may recover at least some of the lost function from that area over time.


Because neurons can make different connections, the associated areas of the health take over.


Now we have that basic structure in place. But experience again is also important. And this is, as I said, the more often that synapse is excited or activated, so just used, the stronger the connection becomes with the neurons involved.


If a synapse is rarely activated, it is likely to disappear.


That just means the axon at one withdraws and adventures and the others move away.


So the human brain is plastic to a point. Its organization and function can be affected by experience, but its actual development does follow some general biochemical instructions that ensure most people end up with brains organized along similar Lines, right?


Like if we were to take all of our brains out, they generally look the same unless there are non normal developmental issues.


Now, linked with this is how does experience work its way into the structure of the brain.


Now, the effect of experience on the brain depends on timing, dose and duration of that experience.


So think back to traditions that we mentioned, but experiences in fact being but again the same kind of concepts, okay?


Timing, dose and duration applied error. We also have to think back to those critical versus sensitive periods, right?


That critical period, that very narrow period of time when a particular experience must occur for development to proceed in a normative trajectory.


That was the imprinting of the chicks, Right. Or we have a sentiment period, which is a developmental stage in which the brain is particularly sensitive to the modification of experience.


Right? Where it's a pin easier to learn a skill like language.


So most in humans, most of our abilities have sensitive period right along the critical periods.


If there are some usually occur in the prenatal period.


That's review right over that. So we know that experience interacts with the unfolded genetic code to produce the brain and intellectual function.


But I again, how does experience modify the brain?


What is the mechanism that allows experience to essentially get inside of our brain?


There are two mechanisms. One is experience expected and one is experience dependent.


When we talk about experience dependent, this is the mechanism of development for storing information that is available to all members of a species.


All humans are exposed to this type of information usually very early on in life.


And so the brain is pre wired to expect this experience.


These are the universal things that it needs to be human.


Right? And the experiences we will have. So there are these partially pre wired areas for these types of experience, right?


So it will have relative synapses in place at birth and takes advantage of the experiences that are common to all members of species, such as patterns of light, dark, various kinds of tastes and odors, and language.


This type of development is enhanced or developed in response to these expected anticipatory experiences.


Our visual cortex has these basic pre wired components in place because it allows us to distinguish one object from another, light and dark, until again those connections are strengthened.


Right? This is why the visual part cortex is also one of the areas that goes through synaptogenesis and my immediation first.


Basically, these experience expected processes of brain development allow infants to take advantage of their expected exposure to these features of their environment.


And then we use them to acquire the related basics, behaviors and abilities.


Evidence for experience expected brain development is found in that overproduction and playing with synapses during several points in development, different portions of the brain undergo synaptogenesis that that he would need by the particular experience.


So this kind of extra step genesis seems to prepare the brain for a range of possible experiences.


And then the user elusive principle comes in sensitive periods.


Because of this kind of overproduction and pretty disease synapses and how it occurs at different periods of development.


This tends to tell us this is why it points to sensitive periods.


That is expecting these experiences to happen during this time frame in which the modification of brain development is at its most efficient and effective.


So this does mean that plasticity does come with a little bit of vulnerability.


Right. If the experience the brain is expecting to use to fine tune those already kind of basic circuits isn't present, the development may be compromised.


So when these expected experiences are lacking during those sensitive periods of development, the brain will fail to develop on that Nordic trajectory.


Language is the easiest one because almost all humans are exposed to language from birth.


Even before birth, really. Right. Evolution has built in an expectation that humans will receive and experience early in life.


If humans don't receive that experience early enough in life, their language will never develop properly.


Right. And parts of the brain associated with language has evolved in a way.


And compares the baby process of learning language extremely quickly.


We even see evidence of this within our visual system.


So babies are born in cataracts. The longer the cataracts are in place after birth, the more important barrier visual immortality will be once those cataracts are removed.


This is because pruning a synapses that would normally be activated by the visual symbolization, they aren't getting that information.


And so those synapses are turned off. In contrast to the synapses involved in the universal experience expected brain development, we also have experience dependent development.


While most humans receive certain experiences early in life, there are a lot of experiences that you have had that are different from experiences that the person sitting beside you has had.


Right. So these experience dependent synapses are not created in the advance.


These aren't species universal experiences. Instead, they are generated in response to specific experiences of that specific individual.


If you have a special skill like you can play the violin that other people don't, or some special knowledge, there needs to be a way for your brain to store that information that is unique to you.


So experience dependent brain development has evolved to allow us to take advantage of new and changing information in our environment.


This is what allows us to learn from experience. If you remember anything while listening to this lecture, you formed new neural connections.


Because of this because this is not universal knowledge.


This is not a universal species thing. These are specific knowledge, specific skills.


And again, anybody played a violin or a string instrument?


What instrument? Guitar is another strange violin. Right. We do see that there are more connections in their brains of people who say play violin devoting to the fingers of the hand, that is the fingering component of the violin because it's a specialized skill.


And so the brain develops in response to that. Kaplan actually looked. They did a study looking at London cab drivers who on average London England who on average spend two years learning the knowledge street names, routes.


They have a larger right campus which is related to spatial knowledge than controls.


The larger they have been on the job, the larger their campus was specialized knowledge.


Their brain responds as well as a lot of the inside changes.


We do see many eliminately changes during the infant's first three months and up to 24 months of age.


Right. We touched upon the essential maturation of central nervous system.


When we look at some of the visual physical changes during the first year those healthy babies will triple in weight and grow approximately 10 inches in length.


Right. So that was that one year mark. Most infants will weigh at 2022 pounds per inch or tank inches long.


And this growth spurt lasts over the first year, levels off and then happens again.


We continue to have growth spurts, but this is a time of loss very great.


You see something similar happen in adolescence.


Now there are many different factors that are involved in growth rate.


It can impact growth rate, diet, genetic contribution, social like memory size, maternal health.


All of these have have their children have links with statistical growth of children.


Body proportions is another one. So increases in the baby's height and weight are accompanied by changes in their body proportions as well.


So when they're born, babies heads are massive in comparison to the rest of them.


Their heads in some cases make up about 70% is is they're still about 7% adult size.


And it'll account for about a quarter of their length of their body.


Right. Everything grows first the top down. Now we do see at around 12 months of age changes in the body proportions.


So there would be they get a little bit longer so their center of gravity lowers making it easier for them to balance, which is right around the time they start walking or attempting to.


We see changes in muscles and bones. Bones are often soft at birth and ossify carbon as minerals are deposited into the and months after birth.


The bones in the hand and wrists are among the first to ossify.


Usually relevant in the first year. And this makes it easier for them to pick things up and play with them.


We also see increases in muscle length, thickness and mass.


And as we see these changes in physical growth, we also see changes in barimotor and elements.


And so again, this is why we're looking at these three different points that are all linked together of today's lecture.


Right. Brain development, problem development disorder, perception.


Right. We're going to take a quick break about five minutes.


So I do suggest a few. Kevin, do your brain dump of what we've gone through today.


And then we'll get into the second part of today's lecture about applied.


Okay. It's a heavy one.


Speaker 2

And cognitive abilities. So what do we know about.


Speaker 3

What.


Speaker 2

Do children know about? What are the processes that children use to acquire the knowledge that they have?


What do children understand and how does that help them adapt to their surrounding?


So when we're talking about cognitive abilities, we're talking about 10 to information preceding information, learning, thinking, representation, and remembering all unobservable events that characterize the human mind.


If you recall from previous lecture, there are a lot of different difficulties in studying infants that all set up the fact that they can't tell us what they're thinking and they can't answer questions that we want them to answer.


Speaker 3

Right.


Speaker 2

And so the questions that we're trying to look at as developmentalists, you know, what mental abilities agents have, what do they know, what are they thinking?


We have to come up with different ways of trying to figure this out.


Speaker 3

Right.


Speaker 2

We'll see some of it in a few different ones in this section of the lecture as well.


When we go through perceptions and motor development, there are other ones as well.


And I have mentioned, if you remember the cat and the hat, the capacity, like with the pacifier.


Speaker 3

Right.


Speaker 2

And the increase. That's one way you'll see this again. The leading researcher that we're going to talk about with regards to, regards to cognitive abilities is a researcher called Jean Pierce.


He founded the discipline of cognitive development.


And you know, he believed that children were actively involved in their own development.


So children from birth and on birth are active mentally and physically in their developments.


He wanted to explain, not just describe development.


And he believed that children think differently than adults do.


And so he tried to provide a theory that gave an overview of the changes in thinking essentially from birth into adulthood.


And his theory and his experiments really did influence and inspire an explosion of research into cognitive development in children.


I'll give you. We'll start with a brief introduction to his theory and then we're going to focus in on what PSJ said about infants cognitive abilities.


You will become intimately knowledgeable about this theory because we will cover, as we go through each kind of developmental stage, we will cover the corresponding theory.


So again, this is just for this session, what we'll be looking at.


If you recall back to the beginning of semester, we had a very brief discussion about the different frameworks and theories.


Hearshay is a constructivist, great framework.


So children are constructing their knowledge through action.


So they're doing this in response to experiences.


So this theory, this theory focuses on the active role of children in their own development.


If you think back to the prenatal developmental Period it was about quantitative stage like shifts, right?


So development progress in the zygotes to blastocyst to the embryo to which are very different, right?


Very qualitatively different. This is the same with regards to PHAs. Here children's cognitive development is seen as discontinuous stage level, right?


So there are qualitative shifts between each one of the stages of theory in the game in cognitive ability.


He emphasized that both biological processes and experience contribute to developmental change.


You have parents, caregivers, maturing brain, the body, all responding to the demands of the environment and integrating all of these observations into knowledge.


So the shocking is theory use infant's knowledge as constructed through action.


Therefore the child is seen as active in their development.


And the differences between stages are qualitative in nature.


So discontinuous. And it also involves both biological and contributions and experience of nature and nature.


So think back to those five principles and hit most of them.


There are three basic components to PHAs. Cognitive developmental theory. We have schemas, adaptations and the different stages of development.


So looking at schemas first the term as it is used by pha.


So according to pha, children's engagement in the world helps them develop schemas.


These are mental psychological structures of models that humans create to represent, to organize and interpret our experiences.


P and Jim called schemas the basic building blocks of intelligent behavior.


Because this is a way of us organizing our knowledge.


It might be useful. It can be useful to think of schemas as units of knowledge, each related to one aspect of the world, including objects, actions and even more kind of theoretical or abstract concepts.


And Piaget believes that newborn babies are born with a small number of innate schemas.


So you put link that if it's easier for you with those experience expected brain development, right?


So even before you know they have much opportunity to experience the world.


These kind of neonatal schemas provide those cognitive structures that underlying components will say there's a need reflexes that babies are born with, right.


That are genetically programmed into us. So babies have a sucking reflex which is triggered by something touching the baby's lips, right?


They suck the nipple, they might suck a super. A dummy wants. They will suck, loosen bigger, but anything near their mouth and their innate reflex is to suck.


And five he because what does that allow them to do?


Eat into love, right. So he assumed, BHA assumed for his observation that the baby has a sucking schema.


Speaker 3

Right.


Speaker 2

They had kind of enduring disposition to carry out this class of action sequences, this organized sucking emotion movements in the in response to a particular class of happiness.


Now, some schemas are gained or learned as the infant, as the person, has different experiences with different situations, people and objects around them.


Throughout development, children learn how aspects of the world relate to each other, collecting this knowledge together in schemas which help them then navigate different events and different relationships in their world.


First by understanding how the parts of the body relate to each other, then how they use their body to manipulate objects, and then how aspects in their world can be represented by words, by gestures, by objects, by concepts.


Now the next component of this theory is this idea of adaptation, which is a process that enables the transition from one stage of his theory to the next.


So this is the inborn tendency to adjust to the demands of the environment.


It is through adaptation that our schemas are developed.


Adaptation itself is a two fold process that happens either through assimilation or accommodation.


These allow for children's schemas to adapt to their increasing experience.


Assimilation is when new experiences are just incorporated into those existing schemas.


So when the infant hears uses an existing schema to deal with a new object or situation.


Speaker 3

Right?


Speaker 2

So this is just the translating of information into a form that fits the concept that the inference already understands.


Sticking with the second one, it enables even to draw milk from a nipple.


But soon enough, nipples aren't the only thing. Maybe it's a pacifier, maybe it's a bottle. So they assimilate the classifier. They assimilate this new object into their existing construction schema and thereby it's strengthened.


So there's no need to modify, it just works.


Speaker 3

Right?


Speaker 2

Accommodation happens when a new experience results in the modification of a required modification of an existing schema.


So an existing schema with an existing unit of knowledge doesn't work to deal with this new object, person, place, thing and needs to be changed in order to for the infant to deal with it.


So again, the adapting of current knowledge in response to new experiences, this is a combination.


So again, sticking with the second schema, say baby picks up and encounters a person's shoulder.


The baby may try to suck on it, so they go to that initial what they know.


However, because of the qualities of a shoulder are not really the same qualities as say a nipple or pacifier.


I don't know what your shoulders look like, does not look like that.


Speaker 3

Right?


Speaker 2

They're unable to just assimilate shoulder into their sucking sequin.


They must make an accommodation in their knowledge base.


So the baby may modify the way that it interacts with the shoulder.


Speaker 3

Right.


Speaker 2

I Have another one. They thrust it into their mouth. That schema is good.


Speaker 3

It fits.


Speaker 2

That sucking schema rattle fits. Does. Now, what if they come across a larger kind of object that doesn't fit?


They tried. It doesn't work. They try. It doesn't work. They have to sit down. Does that make sense, the difference between just assimilation and accommodation?


There is a video. Do I leave the link for you guys in the slide? There is a. So I'm not going to watch it. You can watch it a million times, but it will go through seamless assimilation and accommodation.


It's only about 2 as well, but just you guys can watch it.


So assimilation and combination are usually imbalance, or what is called equilibrium.


Children find that they can revisit most experiences into their existing schemas, but occasionally they need to accommodate their schemas to adjust to new experiences.


When children are spending too much time or much more time actually accommodating rather than just assimilate, the balance becomes, and there's a state of disequilibrium about results when this occurs.


Children reorganize all of their units of knowledge, all of their schemas, in order to return to a state of equilibrium.


And this is what Piaget called equilibriation. And essentially this balance of assimilation and accommodation creates a stable understanding of the world.


This is also the main source of development, and it is more kind of an inclusive or complicated form of knowledge, as the process of biological maturation and the accumulation of experience and accumulation of new knowledge leads to new imbalances, new searches for equilibrium, and still higher inclusive levels of adaptation.


Speaker 3

Right?


Speaker 2

This is because in order to restore balance, outdated ways of thinking, when we can't just assimilate are replaced by qualitatively different, more advanced schemes.


So when you're having to accommodate more and more, that means your knowledge base is essentially out of date, right?


It's not working because you now have a new understanding, a different understanding of the world.


And so your thinking has to adjust. And by doing that, essentially what you do is you turn all those new accommodations into your new base knowledge, right?


And then from there you level out in that stage, and then you assimilate and assimilate.


You assimilate. Oh, these new experiences are now requiring you to accommodate, to accommodate, balance it out.


You reorganize your thinking. So everything becomes a new baseline. But at each baseline, you're increasing your understanding and your knowledge.


Does that make sense? Sense of how assimilation and accommodation leads to adaptation.


Is that a guess? Now, the last component are his Stages. So according to PSJ, there are revolutionary changes in thought that occur three times over the lifespan at approximately 2ish, 6ish and 11 years of age, which divides his cognitive development into four stages.


And within each stage we nicely has six sub stages.


Fun facts, let's keep things simple.


Speaker 3

Right.


Speaker 2

So in the first stage that we'll cover today is the sensory motor stage.


This is from about birth to two years of age. This is when the infant's knowledge of the world is essentially based on sensory and motor skills and motor information.


And the key feature here is about object permanence.


The second stage is the pre operational stage. This is from a mother to six years of age. This is where the child learns how to use symbols to represent aspects of the world and helocentrism and a few other errors and making occur.


Here we have the concrete operational which is his third stage.


This is from 6 to 12 years age. The child now understands and applies logical operations to experiences.


And one of the main concepts here is conservation.


It's just the understanding that something stays the same in quantity even when its appearance changes.


And then the final stage is when the child form of operational station.


And we obtain this in our lessons.


Speaker 3

Right.


Speaker 2

Or adults. This just allows us to think abstractly theoretically.


So it allows us to think about things that we haven't actually experienced and still be able to draw conclusions from that.


So like I said, we're going to focus on the sensory motor birth throughout two years.


We'll cover the other ones as we hit those stages.


So during the sensory motor stage are some of the first examples of the act of the child.


Intelligence develops. This is experience expressed through sensory and motor abilities.


Infants progress from responding to events with reflexes, those ready made innate schemas.


Then this period of history, the stage of theory ends with goal oriented behavior that actually starts to demonstrate awareness of past events.


So during this stage they come to form mental representations of objects and events to hold and picture of a past event in their mind.


And then they are able to start to solve problems by mental trial and error.


As I said, he likes to divide into sub the stages and the sub stages.


So for this one there are six sub stages. Each of these is characterized by more complex behavior than the preceding sub stage.


But there's also a level of complex continuity from substage to substage because each of them is characterization is characterized by variation on a theme from the previous sub stages.


Speaker 3

Right.


Speaker 2

It just. What it means is that the behavior as we go through the sub stages become.


They're repeated. They're varied and they become more forward.


Speaker 3

Right.


Speaker 2

Now, the kind of changes in them, they're changes in the infant's response to its own body.


So we see that in the first couple of sub stages, it's the infant response to objects.


And so its own body is what changes reflexive into oh, I can do this myself, I can make this happen.


And then the next kind of two involve. Or the next few involve creative actions that they can initiate of themselves.


Did I leave this inevitably? Do I video? I'm skimming the videos so that we can get watch the videos because a lot of it just goes over what I'm saying.


Okay, just to give you a different synopsis. So going into the first substate. So this is called the. Or this is kind of your exercise exercising class of activities around birth to that first month and a half.


As I mentioned, the infant is born with a garden inborn reflexes.


And during the first month, the infant primarily exercises these reflexes in a very fixed and kind of present way.


This period is dominated by assimilation, right.


Of different sources of stimulation into those inborn reflexes.


These reflexes constitute the baby's first and they serve as those building blocks for later developmental behavior and development.


The basic needs of coordinating sensation and action is through again these reflexive behaviors.


Even within hours, though we do see neonates begin to modify ne reflexes as a result of experience.


So while this period is dominated by assimilation, we can start to see accommodations happen.


And the infant develops the ability to produce behavior that resemble reflexes, but in the absence of the obvious reflexive stimuli.


So you'll start to see them sucking when there is no kind of contact around their mouth where there's no bottle.


But they might start doing it when they see a bottle and it triggers.


But they're not. It's not the physical trigger. It's an environmental. Does that make sense?


Speaker 3

Right.


Speaker 2

Like the sucking reflex is often a physical trigger, but we see in a combination in which they'll start changing that second reflex on the set, the padlocks, dogs in the belt.


So newborns initially rely on those types of responses to stimuli.


And then some of these become more coordinated with meaningful schemas from the collocation.


And that's just what they're doing that first month and a half after birth.


The second sub stage is called primary circular reaction.


This is about that 1 1/2 to 4 months of age. And this is where they're learning to adapt. So during these early months, reflexes are modified by experiences.


So this stage is characterized by the beginnings of the ability to coordinate various sensory motor schemes.


Infants also engage in self centered activities and take pure pleasure in these activities.


So this is when we see that infants start to defeat leisurely bodily actions for their own sake.


Now, these actions may have occurred by chance, right?


For example, at some point a reflex made their arms do this.


And then the baby goes, oh, that's fine, can I do that?


And then the baby starts doing itself. Because this is fun for the baby, it's no longer a reflex, it has been changed, accommodating adaptation.


And now they're doing this, they're kicking their legs, they're waving their arms because they enjoy it.


Speaker 3

Right?


Speaker 2

So again, that individual schema, that reflexive schema becomes progressively more skilled or coordinated and these reflexes evolve into adaptive schema.


Again, they're more refined, more coordinated.


The chief mechanism for change is the primary circular reaction, the name substitution.


And this occurs when infants use their own bodies to accidentally produce a pleasing event and they try to recreate that pleasing event.


It's called primary because it's the first motor habits to appear.


And because they involve the baby's own body, it's circular, because it's repetitive, it leads back to itself.


So primary circular reactions focus on the infant's own body rather than on the external environment.


And in terms of assimilation and accommodation, the child is attempting to assimilate the motor schema into sensory, into that sensory schema.


So the motor schema as the art into the sensory schema which is looking at it, but the schema where the schemes do not automatically fit.


Several days of apparent trial and error pass, during which infant seems to be trying to make that accommodation so that the schemes will fit together.


So goal directed behavior makes significant advances during the second sub stage, during the first few months after birth.


Speaker 3

Right?


Speaker 2

We even see that during the month after birth, infants only visually track objects that contrast with the background, which is largely automatic.


This is a looking and seeing. Our visual cortex is set up for this from birth, right?


Contrast. By the third month, infants may examine repeatedly and intensely.


They're clearly no longer just looking and seeing.


It's more about looking in order to see, right? It's not just because something came across the vision and they're like, hey, that's something.


Now it's like, I want to look at this thing. So again, during this sub stage, the baby will repeat pleasurable actions centered on its own body, right?


Babies from one to four months will wiggle the fingers, kick their legs, suck their thumbs.


These are no longer reflexive actions. They are done intentionally for the sake of flexible stimulation or the baby.


Okay, does that make sense? In the third subsection, we have secondary sever reactions.


And this is making interesting events. So this typically lasts for about four months, eight months.


So primary circular reaction involves the infant's own body and not other objects.


Beginning sub stage three, as the infant shows greater interest in the world, they start to incorporate objects into those circular reactions.


Novel actions that are repeated with objects are called secondary circular reactions.


Secondary because they're now external to the child's body as objects.


Speaker 3

Right?


Speaker 2

Circular again because they lead to repeating themselves.


So now babies repeat pleasurable actions that involve objects as well as actions still involving their own body.


So those primary ones don't disappear, but we build on them.


An example of this could be the infant who shakes the rattle for the pleasure of hearing the sound that it produces.


They know that the more they shake that rattle, the more noise it will make to the headaches of their candidate.


The first time they shook the rattle, it wasn't intention, it was, hey, what happened happens.


And people, oh, that's a noise. I do it again. They'll make a noise again, and then they'll repeatedly do it, right?


So we see that the infant becomes more object oriented and focused on the external world.


The infant engages in those repetitive actions that produce an interesting change in their environment, right?


They have accidentally discover a particular action or squeezing a toy produces an interesting effect such as squeaking.


And then they will repeat that action again and again because it produces an interesting pleasurable effect for the baby.


Now, it's not necessarily intentional behavior, but it's about prolonging that interesting events.


Speaker 3

That.


Speaker 2

And secondary circular reactions represent an infant's first attempts and efforts to explore the properties and actions of objects in the environment.


So they're not just grasping objects reflexively anymore just simply because something came in contact with their hand.


Instead, they're learning about the sensations and actions that are associated with objects.


But it's also during this sub stage that the infant may start to imitate some simple actions and physical congestions of others.


So they may imitate bowing, they may imitate people who stick their tongue in, but these imitations are still limited to what you can physically do in the sounds that they can physically do.


And again, it's about prolonging that interesting occurrence that's happening.


Any questions with this? Now, before we get into 4 sub stage, I'm just going to introduce the concept of object permanence.


Infancy is characterized by a really egocentric where the child has no understanding of the world other than their current viewpoints, their own points of view.


So the question then remains, does the infant know that an object continues to exist if they can't see it?


And the answer is no. The main development during the sensory order stage is the understatement of object permanence, the fact that objects exist, events occur in the world independently of one's own actions.


So object permanence refers to a set of implicit commonsensical beliefs that we all share about the basic nature and behavior of objects.


This means that when I hold this up and you look at my water bottle, if I put it here, you know it still exists.


It maybe does not. It is out of its viewpoint, and therefore it does not exist.


If the tree falls in the forest, does it make a sound and nobody's around to hear it?


Doesn't make a sound, right? It's this idea that they're like.


Speaker 3

Right?


Speaker 2

And this is because they have. They don't have the ability to form a mental representation of that object in their mouth.


Before five or six, even seven or eight months of age, children don't search for objects that are hidden from their peers.


Even if the infant watches, you hide it, they do not show object permanence.


Quite literally, for them, out of sight is out of mind, which is why peekaboo is so much fun for them, because they literally think you disappeared.


And then the wheel here. Magic, right? Now you understand why it's so fun with them. They're like. You literally are black.


Speaker 3

Okay.


Speaker 2

Hey, look, Lucy, look. It's the clover. Go get him.


Speaker 3

No idea. There. The clipper.


Speaker 2

Look at the cloor.


Speaker 3

My Santa hole. There we are. Good girl.


Speaker 2

Look at rolling transit. Again with the eating is the clipping. Seriously? But that baby just failed. Object permanence went to walk. Oh, you show them. Oh, there they are. While they're literally crawling towards them, you hide them and they're like, where'd they go?


Speaker 3

Where did it go? Right.


Speaker 2

No object from this. So keep that in mind. So moving to the fourth, this formation of secondary circular reactions.


This is using means to achieve an enemy. This happens between 8 to 12 months. Instead of simply prolonging interesting events, now babies will show signs of the ability to use their acquired knowledge to reach a goal.


For example, the infant will not just shake the rattle, but it will now reach out and knock something to the side if it's in front, if it stands in the way of getting pulled from that rattle.


Speaker 3

Right?


Speaker 2

During this stage, the appearance of unmistakable deliberate and intentional Direct behavior.


Piaget called this ability intentionality. This is the ability to engage in behavior directed towards achieving a goal.


So now what we'll start to see is they will lift the blanket to retrieve a toy that has been placed under it, or they will push your hand out of the way to grab a toy.


Speaker 3

Right?


Speaker 2

It's during this stage that you see children engage in means to end type behavior.


So again, they will move things to get what they want and they will now hardly combine and recombine previously learned schemas.


So they will visually look at a toy while touching it to exploring the attack to and Piaget characterized this as the first actual intelligent behavioral patterns and believed that these behaviors were the earliest form of true problem solving.


It's during this stage that Puget believed that infants first shown object from.


Speaker 3

So.


Speaker 2

Again, it's around eight months. Infants will search and uncover a hidden toy and they will start to see, they will start to demonstrate object permanence.


When infants start to demonstrate object permanence, this means that they're now able to hold in their mind a mental representation of that toy.


So now that they know by being able to do this, they know that the object exists even though it's covered, even though what this means is outside is no longer outlined.


Speaker 3

Right.


Speaker 2

She hid it, the baby pulled up the thing, said, I looked back.


They understood that even though they hid whatever it was under the yellow cloth, it still existed.


So that made me showing object permanence, the understanding that even though I can't see it, it still ex.


So during this sub stage, infants will seek to retrieve objects that have been completely hidden.


But Piaget made an interesting observation of the errors that infants at this stage will make and this is known as the A not B error.


Infants will often search for hidden objects where they found it previously rather than where they last sized.


What we saw in the last clip was that if you hide torque completely behind cloth A each time Lincoln will remove cloth A retrieve its way.


What's different in the A not B situation is that while the infant is watching you do the A, hide it under A, hide it under A while they're watching you now hide it under cloth B at different place.


But what we see here is that the infant will still try to recover their toy by removing cloth aim first.


So 8 to 10 month old will still search for their object.


So they're showing object permanence, but their understanding of object permanence is incomplete.


Speaker 3

According to confusion.


Speaker 2

It'S so the baby did the A not the Y.


Speaker 3

Right.


Speaker 2

It continued to look under a. Even though it's 11 went on a theogene claims that this behavior shows only.


Basically shows only a fragmented understanding of objects of objects because infants can't distinguish the objects from the actions that they use to locate, such as lifting a particular cross.


So there's still this level of not full understanding or separation of intent and action and object existence.


They're all kind of I saw it. Oh, here. I looked here. This is where the object now exists and it shall never exist anywhere else except right here.


Because this is where I found it.


Speaker 3

Right?


Speaker 2

It's like when we use our place because we're like, this is where it exists.


Why is it not here? And it's like you have to tell somebody. Did you look somewhere else? Like 5 3rd half of I think still is the in and out video sometimes.


And he puts it in the other places. Now we're going to hit a couple. Before we continue, we're going to hit a couple of the challenges and critiques of his.


Of his theory. Now I'm going to go through these. But his impact and his influence on the ideas of developmental psychology are enormous.


And his views did change people's ideas about how the child sees the world.


And he did have an impact on how we study children.


And again, his ideas generated a huge amount of research which has increased our understanding of cognitive development.


But there are still a few criticisms, even against these first four sub stages.


The first one has to do with a theory. So is it actually the case that children are or are not able to represent objects that they can't find?


How can we measure this as it's not directly observable.


It's an internal process.


Speaker 3

Right.


Speaker 2

Piaget assumed that the resultant historical studies were such because children under the age of 8 months did not understand that the object existed like it.


So they didn't reach for it because they didn't think it existed.


Speaker 3

Why reach for it?


Speaker 2

However, there are alternate reasons why a child may not search for an object.


Speaker 3

Right.


Speaker 2

We'll go through some of the alternate methods, but they may become distracted.


They may lose interest. Therefore they lose motivation research. They may simply not have the physical coordination to carry out the work as necessary as suffering.


When we look at the methods that he used. Several studies have shown that Piaget underestimated the actual abilities of children because his tests were sometimes confusing, were difficult to understand, understand.


Phase methods required sophisticated abilities from the children in order to complete the task.


So they may understand, but they may not have the physical capabilities to complete the task.


PHA's own methods of observation include interviews are open to bias and interpretation.


He conducted his observations often alone.


Speaker 3

And.


Speaker 2

The data collection are based on his own subjective interpretations of the different events that he observed.


It would have been more reliable if Fujian had conducted the observations with another researcher, compared the results after to check that they were similar with that idea of integrated reliability.


So we are going to look at the three alternatives.


So we've got memory, motor skills and extension.


So these are some of the alternatives that may be influencing the child's performance even in these first four subsequents.


So looking at the role of microd, how does an infant's memory impact your performance on say the A0B error test?


Speaker 3

Right.


Speaker 2

This one also looks at motor skills and attention to a certain extent.


There was a researcher named Adele Diamonds and she suggested that infants performances in searching for hidden objects In a now ETAs is limited by their ability to remember and their tendency to perseverate.


So perseveration is just the tendency for infants to engage in repetitive movements rather than shift their movements to meet the demands of task.


So in that first video, sorry the eight of them video, if you.


Speaker 3

Watch.


Speaker 2

When they do put it on their bead, watch what the baby does right.


Speaker 3

Away.


Speaker 2

It wasn't even finished being hidden and the baby was repeating what they had done before.


Speaker 3

Right.


Speaker 2

So that would be. That must be this idea of separation in which they enact this.


It works. They enact it. It works. They're just going to keep enacting because this is a repetitive motion.


Speaker 3

Right.


Speaker 2

And this is what they're doing. So again according to this may not have shifted their behavior to meet the demands of task.


They just are separated in what they did before a repetitive motion of leaning forward and battling.


And so diagnosis suggests that young infants may be capable of representation but fail to aid not be tasked simply because they don't remember where the object is taking.


You combine that you combine and part of this because infants tend to engage in that repetitive motion but rather than shifting they can't meet the demand.


Speaker 3

Right.


Speaker 2

And there is support for this in the fact that they've been found to look so not necessarily there, although baby did look, it's hard to see but they will look at location B as they are reaching to location A.


Speaker 3

Right.


Speaker 2

Now. This is also biological and maturational focus argument.


Maturational changes in the frontal lobe of the cerebral cortex after 6 months of age permits infants to gain some control over their motor responses.


So it does allow them to inhibit the movement to search in the wrong location.


But again, we're starting to see as we went through brain development that isn't always fully developed.


It's a learning, right? That is hidden impulse control. But we can see that they are able. So there are a series of experiments that are conducted in which diamond vary the timing between the switching of the objects from location A to location B and the moment that they allowed a child to reach the object.


And so it was found that at seven and a half, half months of age, the child could correctly find the objects if they're allowed to respond immediate after this.


But even a two second delay between hiding the object and allowing the infant to search for it will result in.


But as they age, as the infant trying to make its age, the delay between kiting and searching is extended by a rate of 2 seconds per month.


So you can delay it for 5 seconds before in a 9 month old, if you delay it by 5 seconds, they'll result in an a 12 months, you delay it by about 10 seconds and you may get an A, not B error.


And so this suggests that they are capable of representing objects they can't see, but they quickly forget location or they come either not engage in money or may look in the last place they found.


And if you think back to brain development, it's that coordination of all of those networks are not issues because you have to now coordinate from the hipp canvas into, you know, the prior alone and the frontal cortex to be able to coordinate the memory of where you saw it last, where you saw it presently, how to move your hands and your arms and all of these things.


Speaker 3

Right.


Speaker 2

Does that see why I did brain development first and how it leads to motor development and perceptions?


Yes, just shake your head now again, under certain circumstances, 9 to 10 level lifts will not show need, but there is a certain degree of maturation of the frontal lobes that is still needed because of the development of working memory and attention.


Hey guys, good job. Obviously that baby passed the anal right? Now what about how might their motor ability affect performance on PJ's task?


And this is very reaching and moving, right? So we're going to go through habituation and violation of expectation settings.


And this has these ones remove the need for motor skills.


So basically at this point you development the infant doesn't have that integration, that coordination between the various systems, the brain, your muscles and the skills necessary.


Because you have to, in order to do this, you have to look, you have to proceed, you have to remember, you have to reach.


There's a lot of integration that's happening in order to accomplish PSA's a task to get around this remaining colleagues, I cannot say the French last name, first name.


Designing different type of tasks to test the infant's understanding of object permanence and their ability to form mental representations of their roles using habituation settings.


Habituation is just that gradual reduction of strength and response as a result of repeated stimulation.


So if you repeatedly expose babies to a physical event or an object, they will stop looking at that event or object.


Speaker 3

Okay.


Speaker 2

The same is if you live on a busy street and you first move in, you hear all of the sounds and you become habituated to those sounds and are less likely to hear them the longer you're exposed to it.


You have this happen to us as well in the violation of expectations.


So using habituation, it was explored as from habituation.


So we'll look longer at a possible event, right? This is a variation of the first event that follows physical laws or will they look at an impossible event, which is a variation that bibles is the lawsuit.


So recovery to impossible events suggests that an imperial is surprised or notices a deviation from physical reality.


Violation expectation studies exploit the well known tendency of infants and everyone to stare at events that violate our expectations.


The premise is that if an infant, if infants are capable of mentally representing their experiences, they should develop specific expectations during that habituation phase, that repetitive I under a I, under a I under a sort of kind of IP phase.


And they will look longer at events that violate those expectations, those impossible events.


So looking at a study, infants 4 months of age were first shown this green rotating back.


And after a while they will just, I guess you could say get bored, but they will stop looking.


They become habituated to this and they stop looking.


After they habituated, a box is placed in the back of the screen.


This shows the possible event. The screen stops when it reaches the box.


Speaker 3

Right.


Speaker 2

Next what we do is the infants were shown the impossible event.


The screen rotates the full 180 degree arc as if the box were no longer behind it.


This violates the idea objects exist permanently.


Speaker 3

Right?


Speaker 2

If an object exists permanently, the middle one should happen.


If objects don't exist permanently, permanentity, then the problem would happen.


So PJ said they didn't understand object permanence until seven months, right?


Speaker 3

Eight months.


Speaker 2

Just a formality, right. An infant who understands will find that impossible, understands object permanence, will find that impossible event, a truly novel stimulus and look longer at it in comparison to the possible events.


Speaker 3

Right?


Speaker 2

Now what was found is that infants as young as three and a half months old stared longer at the impossible event at 183R.


What this demonstrates then is that infants do believe that the possum teacher exists as a digital entity.


After it was visibly obstructed by the screen, the infants realized that the screen could not or should not be able to rotate through that space that is occupied by the box and expected the screen to stop.


And we were surprised when it did not. The question is but why then did stop actively look for hidden objects until about eight months of age?


While it's likely as a result of the inability of the coordination of all of the components that are required to do that, like you know, removing a barrier in order to reach for a story, remembering the coordination of all those different components of cognition, perception and motivation, these do not occur until later on until that 18 month privilege.


So they can't coordinate the necessary perception with their vulnerability yet, but they're demonstrating cognitively that they understand object.


So again it's something about clinicians past development and that this is another example.


So again there are properties of a physical world other than objects continuing to exist from out of sight.


A number of studies using the violation of expectations method were used to look at when infants appear to have at least an initial grasp of the physical laws concerning the behavior of objects.


So this was used on two and a half month olds testing again their expectations of height.


So you first habituate them to this first thing where the parrot goes across.


In short, it's, it goes across. If you put more slides into presenter mode, these work for you.


The animations work, right?


Speaker 3

And then.


Speaker 2

This is the impossible event. This carrot is small when it goes to this one you should see the top of it, but you don't, right?


And so they build two and a half months of age, they will look at this impossible event longer than they do the possible one.


So another looked at whether young infants would expect an object that is suspended unsupported in mid air to fall.


The experimenters repeatedly presented four and a half year old infants with habituation event shown as that possible event.


Speaker 3

Right.


Speaker 2

Next they were shown an impossible event in mixed with WAPIS poison all the way to the edge, but does not fall in a suspension, right?


Infants looked longer at that impossible event, indicating to the researchers that the babies expected the blob to fall.


Now there are still some criticisms with regards to the body, but again studying infinity is very difficult.


Speaker 3

Right?


Speaker 2

One of the questions that we have to look at is what does the image look at the 108 degree screen movement as opposed to the 120 because it's just a grading movement.


So we're making inferences, we're drawing conclusions and making inferences based on what we think.


So this positive question about whether or not what these studies are measuring is actually valid, are we actually measuring what.


Speaker 3

We think we're measuring?


Speaker 2

We hope we don't.


Speaker 3

Right.


Speaker 2

Some of this is also around the idea that we're contributing attributes to infants.


This one is we're contributing the fact they understand gravity, right?


Physical laws that if you put something and there's nothing underneath it can be really attributable reasoning, expectations, inferences and surprise to infants.


Speaker 3

Right?


Speaker 2

So again, there's always this issue, are we actually measuring what we think we're measuring?


Now, even if infants are aware of or are aware of physical properties of objects, according to Piaget's theory, they cannot reason about these objects, right?


They're not meant to have this level of reasoning.


So one question that has been asked is, can infants count?


This question was addressed and tested by Karen Wynn and she found that infants 5 months of age look longer at, again, excuse the execution violations impossible.


Measuring the number of objects, involving the number of objects expected.


So if it started with one null, right? Then you show one doll being added. They will look longer at three dolls than two if the result is three dolls.


So it's not just a change that matters, it's the amount left, but the amount that also matters for them.


So four month old agents were shown the events at the top of the figure.


The screen was then lowered in half. The trials were dealing two dolls, a possible death.


And in the other half we have only one dog, which is impossible because they see two dogs.


The infants looked longer when there was only one dog, suggesting that they had mentally calculated, mentally calculated the number of dolls that ought to have been behind the screen.


So what this and others have actually shown is that infants are capable apparently of making simple arithmetical math, operations math, variable math, single math.


Speaker 3

All right?


Speaker 2

Far ahead of Piaget's timetable regarding their ability to reason about and mentally represent objects.


Now this isn't suggesting that they fully understand or comprehend.


What matters is they're just noticing that there's a difference.


This moves us into his fifth sub stage. This is the tertiary. This is the beginning of symbolic thoughts and experimenting.


So this is about experimenting. This is tertiary circular reactions. It's about 12 to 18 months. He called this BH, called this stage the discovery of new means of active experimentation.


He looked at the behavior of infant in this stage as being characteristics of budding Scientist.


So this is where he said children are now exploring and experimenting with their environment.


It's characterized by active tr, trial and error exploration.


Infants will now engage in again, tertiary circular reactions or purposeful adaptations of their established schema to specific situations.


So nimpy will repeat old schemas of objects and try to understand why different objects and different interactions with them result in different.


Speaker 3

Behavior.


Speaker 2

Now takes on a new kind of experimental quality. And they can state barrier actions dozens of times in a deliberate trial and error fashion in order to learn how things work.


But they don't seem to have the ability to reason systematically about actions or to anticipate, anticipate probable consequences or outcome yet.


So again, infants purposely explore new possibilities with objects continually changing what is done to those objects and exploring the results.


And if any, substage 5 might deliberately shake a number of different objects, trying to discover which produces sound, which do not, and what type of sound.


They realize that a ball can be thrown, it can be kicked, it can be bounced.


Can these other last things? You bet they'll find out it's rounded, it looks like a ball.


So these skills, these behaviors build on the accomplishments from stage four.


Curiosity and interest in novelty starts to emerge.


So babies repeat actions with different objects solely for the purpose of seeing what happens.


So they may just start dropping cutlery and then they see what happens.


Sometimes parents put it up, they put it back down.


Other sometimes it makes a mess and make noises, but they continually just do it because they want to see what happens.


And this is also where he says problem solving skills are starting to emerge.


So there was an example in which he gave his daughter a stick.


A crib and stick observation exam. In his daughter gives sticks and daughter the crib gets, but she goes outside the crib.


And so she has to reach through, grab the stick, and if she wants to explore, she has to bring it back into the crypt.


Well, depending on how she grabs that stick attended, it's not going to be right because it's going to get stuck in the other slats of the crib, right?


And so she needs to go through that physical trial and error of getting a stick into it grid, Right?


But again, it's physical, it's not mental, right?


At this stage, you have to physically do it. And so the infant who once explored an object from taking it apart now may try to actually put it together.


So now we're starting to see they may start to build things, right?


They may stack bricks that they took everything to the truck back again and put back those Nesting cups as opposed to taking them apart.


They might not be all right in the right size, but they try, we try this little trial here.


They still live in the here and now. So again, you know, it, it takes that physical form.


It's that external exploration, the ability to mentally plan, to organize and to envision their actions and foresee their possible consequences.


Does the of the arrival of representative representational thinking, which is in the next stage, the last one.


So in this stage they're acting first. The next stage is where they start to think before they act.


So this is the last sub stage. And this is the beginning of symbolic representation, of mental representation.


This is about 18 to 2 years. Again this is what we're starting to see, the beginning of the ball of thought.


This is the transition to pre operational stage of cognitive development.


That's the next stage. Babies can now form internal mental rest representations of objects.


And the emergence of symbolic representation marks the end of the sensory motor stage.


So once they're able to mentally represent things, they're now moving into the second stage of cognitive development.


But during this six sub stage, children are able to problem solve more internally without accident, every possible solution.


And so this is a stage where external exploration is starting to be replaced with mental exploration.


And they become more able to mentally work through simple problems that present themselves to the child at this stage.


And corresponding developments are important because once infants are able to represent a sequence of events, they can start to solve problems more systematically than through physical trial and error.


Again, if you remember sticking occurred in this substage, the infant instead of engaging or father instead of engaging that invert, lets just try to stick through until it comes through.


They now have the ability in their mind to make a couple errors still physical, but they'll realize that oh, if I do it this way it's not going to work.


And in their mind the idea is that they'll say maybe if I rotate it and then they can do it.


They're able to use that mental representation and think through without having to physically do every iteration in your problem solving.


And this suggests that they are mentally representing the stick and the bars are crib.


They're able to perceive that the stick will not fit as it is.


They must then rotate that mental image of the stick in their mind until they are able to perceive position in which it will come through the box.


So this shows that they're able to visualize things mentally and they're not that are not necessarily physically present.


And this is crucial to the acquisition of object permanence.


As well. And this development of symbolic ability allows for a large number of new abilities to develop.


Deferred imitation being formed. Where they see somebody do something next, now it's 24 hours, 48 hours, three weeks, six months from now, where they will imitate that person.


Speaker 3

Right?


Speaker 2

Symbolic play. When that cereal box can be a car or bed, a cloth can be a blanket or a key, right?


We also see the emergence of language because what is language but symbolic representation of what we are saying?


Letters are just symbols, sounds are just components, and they represent something.


And so we're starting to understand that these sounds that we say means something, they represent something.


They're a symbol of something. When I say ba, ba, it means something. It's not just a consonant and a vowel put together.


Speaker 3

Right?


Speaker 2

It represents a va or milk or whatever. It represents a basin. So again, what we're seeing is that, you know, in this state stage, the toddler uses mental combination intellectual experimentation and imagination.


That really does go beyond and supersede the active child and therapy.


Substance class is something more. It is something qualitatively different. I'm just going to go through this one because I just.


I want to make sure you understand this, okay? So I'll record from this and then obviously I'm going to record the perception and Motor Development 1 and the Social emotional.


So you'll have everything. The idea is that I want to have all of this up for you by tomorrow evening.