Psych 1XX3 exam

Androgen insensitivity syndrome

when individual is biologically male but resistant to male hormones (androgens), affecting the development of male characteristics

Development

Changes and continuities that occur within the individual between conception and death

Maturation

Biologically timed unfolding of changes within the individual's genetic plan

Learning

Relatively permanent changes in our thoughts, behaviours and feelings as a result of our experiences

The acquisiton of neural representations of new information

Can make controlled processes automatic

Interactionist Perspective

The view that holds that maturation and learning interact during development

Biological maturation restricts the timeline of learning from the environment

Learning from the environment modulates the maturation of human process

Need input from outside world

Habituation ( Method of measuring abilities in infants)

Test an infants ability to detect novel stimuli

Present infant with same stimulus

Measure physiological responses/behavioural

Can be used to test colour preception

Event Related Potentials

Indicate changes in neural activity

Changes in brain activity in specific areas to indicate response to certain stimuli

Electrodes placed on scalp-> detects activity in neurons

Particular behaviour being measured will evoke changes in various brain regions of interest

High amplitude Sucking Method

Rate of sucking indicates level of preference

Measure baseline sucking rate

Faster sucking -> Preference for stimulis

Preference Method

Level of attention to one stimulus relative to another indicates preference

Babies enjoy- big patterns, Black/white contract, human faces

Competence-Performance Distinction

Individual may fail a task, not because they lack those cognitive abilities, but because they are unable to demonstrate them

look at age of kid before giving task

Developmental Research Methods

Look at how certain abilities change over time

Longitudinal Design

Same individuals are studied repeatedly over some subset of their life span

Selective Attrition

Loss of participants> sample ends up being non-responsive of the population as a whole

Cross-sectional Design

Individuals from different age groups are studied at same point in time

Cross-sectional design advantages

Assess developmental change

Less time consuming

Less expensive

Can uncover age differences

Cross-sectional design Disadvantages

Cannot distinguish age/generational effects

Can't directly assess individual developmental change

"Cohort Effect"

Quasi Experiment

subjects not randomly assigned

Grouped based on variables (Age, gender, etc)

Dizygotic twins

~50% shared genes

Different sperm/ovum

Simple dominant-recessive inheritance

Expression of a trait is determines by a single pair of alleles

One allele is inherited from each parent

Together , the pair of alleles determine phenotypic expression

Dominant allele expressed in phenotype

Recessive allele not expressed, but heritable

Phenotypic traits governed by multiple pairs of genes

Polygenetic Inheritance

Expression of trait is determined by the interaction of multiple genes

No single gene can account for most complex behaviours

Codominance

Expression of trait is determined equally by two dominant alleles

EX. blood type

Offspring expressed both equally

Sex-linked Inheritance

Expression of trait is determined by genes on the X chromosome

responsible for colour blindness/hemophilia

Phenotype expression of the recessive allele occurs less frequently in females bc only 2 X chromosomes

Rarely express sex-linked recessive genes

Extreme Behaviourist POV

Nuturists believe external factors alone ultimately influence development

(Watson)

• believe only observable behaviours are worth studying

The Genetic POV

Naturists believe genes predetermine the path of development

Some developmental processes are buffered against environmental variability ex. all infants babble the same

Canalization principle

Genotype restricts the phenotype to a small number of developmental outcomes

Range of Reaction Principle

Genotype establishes a range of possible responses to different kinds of life experiences

Range of one's potential height is limited by genetic factors

Poor/optimal environment influence expression

Passive Genotype/Environmental correlations

The environment your parents choose to raise their children in was influenced by the parents own genes

Environment compliments your genes

Evocative Genotype/Environmental correlations

Traits we have inherited affect how others react to/behave towards us

Natural temperament determines how others behave around you

Active Genotype/Environmental correlations

Our genotype influences the kind of environment that we seek

Early in life, passive genotype correlations influence you the most

Active genotype correlations influence ou more in childhood/adulthood

Choice of enivronment

Twin studies

Unveil the role of genes in developing traits

Twins raised apart had higher correlation of grades than dizygotic twins raised together

Suggests genetic factors may play larger role in intelligence

Critical Periods

Window of opportunity within an individuals development in which particular environmental stimulation is necessary in order to see permanent changes

Kitten visual study

Visually deprives for first 6 weeks of life, kitten 1 s unable to discriminate visual patterns

Kitten 2 was deprived for 6 weeks after 4 weeks of age, and is able to

More connections in neurons in enriched environment

Experience-Expectant Brain Growth

Brains expect a certain amount of environmental input and with this input, our brains develop naturally

Experience-Dependant Brain Growth

Our brains develop according to our own personal experiences

Flexibility of timing and type of stimulation required for normal development

Normative Research Q

how things normally change age to age

Analytic Research Q

how processes and variables that are responsible for changes in abilities from age to age

Cohort Effect

Disadvantage of cross sectional design studies

differences between age group might be reason for difference instead of actual differences in development

Neural development begins?

3 weeks post conception

Neural Tube

Neural plate folds and closes to become this, then leads to development of brain and spinal cord (CNS) lined w stem cells

When are the forebrain, midbrain and hindbrain visible

28 days, distinctly human by 100 days, sulci/gyri dont form till 7 months

Synaptic development

rapid increase in number of synpases in first few months

At 1 year, it begins to decrease until 10 years of age

Ocular dominance columns

visual cortex, synapse with neurons carrying info from each eye

Experience-expectatnt

area of dominance columns for both eyes is the same

Brain expects same strength input from each eye

Experience-dependant

Only develop typically if one receives the appropriate input (Kitten Study)

Amblyopia

Lack of processing power in ocular dominance columns receiving input from that eye due to previous deprivation

"Lazy eye"

Patching

Cover stronger eye, competing for cortical space, allows weaker eye to strengthen its connections

Adolescence

another wave of synapse production/subsequent pruning

Frontal lobe>responsible for self-control, judgement, emotions, organization

Neurogenesis

new neurons created

Occurs particularly in hippocampus/olfactory bulbs

May play role in learning/memory

Occurs in brain areas that are typically non-neurogenic

Experience-dependant plasticity

"Use it or lose it"

Fluid intelligence

abstract thinking and quick reasoning, tends to decline with age

Crystallized intelligence

an individual's accumulated knowledge

May increase with age

Why might cognitive intelligence decline

cerebral blood flow

death of neurons

individual difference

genetic + enviro

Longitudinal studies proved cognitive decline isnt bc of age

Aging + memories

Older people better at meaningful info recall

Younger adults better with working/episodic memory

Natural Selection

Charles Darwin, Russel Wallace

Mutation, genetic drift, migration

Differential survival and reproduction of organisms as a result of the heritable differences between them

Favourable traits are selectively transmitted across generations

Three components of natural selection

1) Individual differences

2) Differential reproduction

3)Heritability

Two subtypes of sexual selection

Mate choice> weapon/display

Genetic health> best mate

Species-specific behaviour

Physical form

Habitat preference

Group size

Social system

4 types of social behaviours

Cooperation- both benefit

Selfish- Recipient does not benefit, actor does

Altruism- recipient benefits, actor does not

Spite- no one benefits

"trade off"

animal is vigilant watching for predators

reduced in groups

Inclusive fitness

Direct; personal reproduction

Indirect; reproduction of close genetic relatives

Hamiltons rule

The reproductive benefit to the recipients(B) multiplied by the probability that the recipients actually have identical copies of the same gene or coefficient of relatedness(r) must be greater than the reproductive cost to the actor (c)

rB>C

eg 5 siblings

r = 0.25

b = 5

1.25 >1

Relatedness to half siblings or aunts or uncles

.25

Hymenoptera

Individuals living to serve colony (bees)

Some dont reproduce

Aggression is lower between nests of closely related colonies

Kin recognition

Mothers association

Coresidence w other children

Phenotype matching

Evaluation of relatedness between individuals based on an assessment of phenotype similarity

Not necessarily conscious

Prosocial to those who look like us

Investment game: More trusting of those who look like kin

Reciprocity

Why we help those who dont look like us

Direct/indirect (reputation)

Phylogeny

Pattern of divergence of distinct evolving lineages from common ancestors

Fluctuating asymmetry

measure of bilateral (I vs r) traits that are symmetrical over the population as a whole but not necessarily for any given individual. The optimal body tends to be symmetrical

Sexual jealousy

guard a mate or sexual prospect from engaging in sexual activity with potential rivals *prone to men

Romantic Jealousy

Guard a mate w/ sexual prospect from leaving the relationship to form a new w/ potential rivals

direct fitness

effect of its actions on own reproduction (c)

indirect fitness

reproduction of recipients

Cues of kinship

Caregiver

Maternal- perinatal association--> recognize younger siblings

Co-residence duration

Phenotypic similarity

Receptive zone

receive signals from other neurons

dendrites branching out

cell body/nucleus

Passes down axon when signal is recieved

goes down axon terminal and to teriminal end (release signal)

Transmission zone

send signals to other neurons

axon

axon terminal

Glial Cells- function and locations

Structural support, nourishment, insulation

Rest in bath of ions, chemicals and blood vasculature

1- Resting potential

Ions in extra/intracellular fluid have (+) (-) charges

electrically inbalanced (-70mv)

Concentrations are result of the balance between electrostatic pressure and diffusion

K+ ions are in higher conc inside of the cell, so the force of diffusion tries to push them out

Inside of the cell is more negative so electrostatic forces attract K+ into the cell

2 forces balance out

Baseline imbalance

neg charged ions (proteins)are too large to cross

Leaky Potassium channel always open

Much of the potassium (K+) remains inside

Cl ions are mobile, but the proteins keep them mostly outside cell, low conc through sodium channel

Cl Less important to resting state of neuron

Cl/Na found primarily outside cell

The threshold

Nearby neurons and random ion flow fluctuate the resting potential

-50mv is threshold

2 ACTION POTENTIAL

1 Na+ channels open

> When membrane potential is below -55mv

>When reaches threshold, the gate opens Na+ rushes in

>Membrane potential rises to +40mv

>Force of diffusion is rapid, charge is more (+)

Electrostatic force begins to push some K+ ions out of the cell through LEAKY potassium channel

2 Voltage-gated K channels open

>When membrane becomes depolarizes

>K+ rush outwards

>Peak voltage reached, Na+ channels close

3 Voltage gated K channels close

>Once it reaches RP again

>Sodium channels reset

>Inside of the cell loses pos charge (0mv)

>Falls below threshold

4 Refractory period(-100mv)

>Return to resting potential

Refractory period

(-100mv) cannot fire another action potential until it recovers

Sodium Potassium Pump

along cell membrane

removes sodium from cell and replacing potassium

3 Na+ OUT

2 K+ IN

moves slowly

uses extensive energy

Ion balance of neuron

Special Glial cells coat axon

Myelin

Enhances the traveling speed of AP down an axon

Oligdendrocytes (CNS)

Schwann (PNS)

Excitatory Postsynaptic Potential (EPSP)

Excite the post-synaptic neuron towards action potential threshold

Sodium channels open, allowing some pos changed Na ions to flow into post synaptic cell

This depolarizes the cell, moving away from -70mv and closer to -50mv threshold to fire

A number of EPSPS must occur to reach -50mv threshold

temporal summation> Can occur one after the other

Spatial Summation>multiple EPSPs generated simutaneously from different presynaptic neurons

Inhibitory Postsynaptic Potential (IPSP)

Cl channels on cell membrane open, allowing negatively charged Cl- to enter inside the cell

Neuron is hyperpolarized as resting potential is now even further away from the threshold

ventricular zone

lined with founder cells

Neurogenesis steps

Begins as neural plate, folding into tube, eventually becoming CNS (18 days +)

Cells migrate outward from ventricular zone

Day 28-42 cell division is symmetrical as the division of each founder cell leads to 2 identical founder cells

Day 42-125 "asymmetrical" One founder cell> becomes one glial cell or one becomes neuron cell

Neuron Migration

begins almost immediately after first neurons are born at day 42, continues for 6 weeks after last neuron is born

Neurons almost always produce glial cells

EXP: radial glial cells

Fibres that extend outward from ventricular zone, like scaffolding

End at the outer layer of the cortex

Use these cells to migrate from ventricular zone to cortex

Deepest layers of the brain developed first

After reaching destination, neuron differentiates

Differentiation is sensitive to input a neuron receives from its connections to other neurons

Neuron development

Input from other cells effects this

Need certain neural input

Need to mature by growing dendrites, axons, synapses

Need neurotrophic factors from other neurons to stay alive

Compete for neurotrophic factor

Other neurons pruned away

Neural connections also pruned

Synapses begin to decline after prime, this increases processing efficiency

Rene Descartes

"Dualist"

Body was like a machine, the mind was a separate and non-physical

Seat of the soul was in pineal gland

Efferent nerve fibres

Fibers that carry info outward from CNS to the periphery of the body

Afferent nerve fibres

Fibers that carry info inward to CNS from the periphery of the body

PNS- Somatic

receives info from sensory organs and controls the voluntary movements of muscles

Brings us info we are consciously aware of

Allows us to preform actions under conscious control

PNS- Automatic

Controls involuntary movements outside our conscious control

Regulates smooth muscles, cardiac muscles, glands

Causes certain orgrans to contract

ANS- Sympathetic

Preparing body for emergencies (fight/flight)

Increases heartrate, dilation of pupils

Dilation of the internal structure of lungs

Inhibition if digestion and contraction of the bladder/rectum

ANS-Parasympathetic

Slowing of the heart

Lowering of blood pressure

Contraction of pupils

Increase in activity in gastrointestinal tract

Secretion of digestive juices

Conserve/increase the bodys energy sources

Dendrite

Branched projections that conduct nerve impulses received from other cells to the cell body, usually very short

Covered in tiny spires, where connections from the axons are made at a junction known as synapse

Bring together impulses occuring across the many thousand of synapses to their final destination of the cell body

The cell body

Many of the specialized proteins/enzymes that participate in the metabolism of the cell are synthesized from the DNA templates coined in the nucleus

The axon exits through the cell body from an elongated portion called the "axon hellock"

The axon

Terminal boutons are where connection to the dendrites are made

Surrounded by Myelin Sheath

>Insulate/speed up conduction of the AP

"White matter" of brain composed mostly of myelinated axons

Interneurons > Multipolar

Comprised of multiple dendrites extending from the cell body and only a single axon

Interneurons >Bipolar

Only has single dendrite exiting one side of the cell body with a single axon exiting the other

Usually sensory neurons that dendrites terminate at receptor cells

Interneurons >Unipolar

Only has single dendrite leaving the cell body which eventually branches in 2 directions, one leading to the dendrites and the other along an axon