Prenatal Development

1. The role of genes; epigenetics

   • Epigenetics: changes in your environment will increase of decrease expression of a gene

     • Changes in gene expression without modifying DNA

     • E.g. changes in brain development resulting from parents’ drug or alcohol use during gestation

       • Say parents were using one drug/substance during gestation for child #1 and another substance during #2, they will develop differently

     • A gene may be active in one person and not another, of within different cells in one individual

   • The way genes affect our development is complicated

     • We have more than 20k genes

     • You can't exactly predict how people will develop based on their genes

     • In almost all cases, single genes are not responsible for a single outcome

     • Our development/outcomes are polygenic

2. Period of the zygote, embryo, fetus and milestones within each

   • The period of zygote (or germinal period)

     • Shortest stage of prenatal period (2 weeks)

     • Zygote divides and grows in complexity

     • Travels to the uterus

     • Implants in the uterine wall

     • Placenta forms

   • The period of the embryo

     • 2 to 8 weeks

     • When embryo grows

     • Significant growth occurs in the major organs and body systems

     • Embryo has three distinct layers:

       • 1. Ectoderm -- forms skin, hair, teeth, sense organs, brain and spinal cord

       • 2. Endoderm -- produces digestive system, liver, pancreas, and respiratory system

       • 3. Mesoderm -- becomes the muscles, bones, blood, and circulatory system

   • The period of the fetus

     • 2 to 8 weeks

     • Is about 1 inch long

     • Appears to have gills and a tail like structure

     • Has rudimentary eyes, nose, lips, and teeth

     • Has stubby bulges that form arms and legs

     • Undergoes rapid head and brain growth -- 50% of it's length and 100,000 neurons in a min

     • Nervous system starts functioning around the 5th week, producing weak brain waves

     • How development proceeds:

       • Cephalocaudal development: pattern of human growth proceeds from the head downward

       • Proximodistal development: human growth occurs first in the central areas and then extends outward

       • Teratogens are most harmful during this period

   • Period of the fetus

     • 8 weeks to birth, longest stage

     • Fetus undergoes rapid change

     • Increases in length about 20 times

     • Proportions change

     • 2 months: 50% of length is the head

     • 5 months: ⅜ of length is the head

     • Birth: ¼ length is the head

     • Fetus substantially increases in weight

     • 4 months: weighs about 4 ounces, can feel them move

     • 7 months: weighs about 3 pounds

     • birth : weighs just over 7 pounds

     • Organs become differentiated, begun to function

     • Fetus can hear and feel vibrations of sound

3. Sensory capabilities of the developing fetus

   • Vision:

     • Typically cant see further than 8-16 inches away from their face

     • Can discriminate levels of brightness

     • Can distinguish different colors and may have color preference

       • Through infancy, favor high-contrast images/toys/objects

   • Hearing:

     • Evidence for hearing as early as 7 months gestation (before birth, aka 7 months from conception)

     • Exhibit familiarity with certain sounds

     • acuity /accuracy is not fully developed

   • Touch:

     • most well-developed sense at birth

     • Respond to stimuli (reflexes) and pain

   • Smell and taste:

     • Well-developed

     • Pucker lips when a sour taste is placed on them

     • Respond with suitable facial expressions to other tastes

4. Teratogens during prenatal development

   • Teratogens are most harmful during the period of the fetus (2-8 week period)

   • Effects of teratogens vary with time

     • Period of the zygote: relative impervious

     • Period of the embryo: most deleterious

     • Period of the fetus: minor damage

   • Hard to pinpoint the primary cause of damage:

     • Effects differ from different individuals

     • Cumulative effects are common

     • Race and socio-economic status (SES) are influential factors

   • Teratogens:

     • The effects of substances on prenatal development resulting in negative outcomes (e.g. low birth weight, underdevelopment, etc.)

     • Outcomes are affected by dose, cumulative effects, and sensitive period (times of rapid physiological or behavioral development

   • 4 categories of teratogens:

5. Physical teratogens, high heat

   1. Saunas, hot tubs, or infections that raise body temperature to 102 degrees fahrenheit or higher

   2. Associated with neural tube defects, spontaneous abortions, and various cardiovascular abnormalities

6. Metabolic conditions affecting pregnancy

   1. Metabolic conditions affect the process of converting energy from food, affecting the development and function of the body

   2. These include: malnutrition, diabetes, and thyroid disorders

7. Infections

   1. Rubella virus, herpes simplex virus, covid 19, and syphilis can cause congenital abnormalities

8. Drugs and chemicals

   1. Radiation, heavy metals (including lead), insecticide and herbicides, prescription and over the counter drugs, illicit and recreational drugs, alcohol, cigarettes, nicotine, caffeine, and even some vitamins

The Newborn & Infant/Toddler

1. APGAR scale: assesses need for intensive care for babies after birth

   • Conducted 1-5 minutes after birth

   • Measures: heart rate, respiration, muscle tone, reflex response (babinski)

2. Low/very low birth weight vs small for gestational age

   • LOW BIRTH WEIGHT

     • Low weight: less than 5.5 lbs

     • Very low: 3.25

     • → difficulty maintaining ok body temp, more risk 4 infection, increased risk of cerebral palsy

       • preventable w/proper prenatal care

     • possible cause of lbw: preterm baby - early birth triggered by any disruption to mother→ release anti inflammatory

   • SMALL FOR DATE/GESTATIONAL AGE

     • Weigh less than 90% of all babies the same gestational age

     • VERY SERIOUS bc growth negative affected

     • Mortality rates 4 times higher

3. Sensory capabilities of the newborn (old misconception: bb has minimal abilities)

   • Vision

     • Typically can’t see farther than 8-16 in

     • Can discriminate levels of brightness

     • Can distinguish diff colors and color preferences

       • Typically: favor high contrast, images toys and objects

   • Hearing

     • Evidence for hearing as 7th months gestation

     • Exhibit familiarity w/sounds

     • Acuity is not fully developed (20/400 vision)

   • Touch

     • Most well dev sense at birth

     • Respond to stimuli (reflexes) and pain

       • Ppl used to believe that they didn’t feel pain so they didn’t give them pain meds 🙁

   • Smell and taste

     • Well dev

     • Pucker lips when sour

     • Respond w/suitable facial expressions to other tastes

4. Reflexes in newborns

   • Reflex: involuntary mvmnt in response to stimuli

     • unlearned, organized, involuntary

     • Rooting, swallowing, sucking (food)

     • Soughing, sneezing, blinking (protect from pathogens)

   • Some leave (Babinski) other stay (blink, swallow, sneeze, gag)

5. Physical qualities/development (how infants grow, brain changes, typical weight and height gains)

   • Growth

     • Newborn Weight and Height

       • Avg weight 7.5 lb

       • Avg height 20 in

     • Head goes from 50% of length (in womb) → 25%

     • 2 ways humans grow

       • Cephalocaudal growth: head first

         1. Big ass anime baby heads

       • Proximodistal: grows from the inside out

   • Brain Changes/Dev

     • Neurons: nerve cells (slides)

       • Constantly form new and stronger connections

       • Plasticity: ability of brains to adapt to change (ex: enviro and damage)

       • Sensory and experiences affect size of individual neurons & interconnections

         1. Enrichment valuable bc sensitive period (ex: cuddling , talking, singing)

     • Development (book)

       • ,brain 25% of adult weight

       • Most neurons are present at birth but not fully mature

   • Typical weight and height gains

     • Initial, temporary 5% of body weight followed by period of rapid growth

       • 4 months: 2x birth weight

       • One year: 3x b weight

         1. 26-32 in

       • age 2: 4x b weight

     • 2 important hormones

       • Human Growth Hormone (HGH): influences ALL growth except for CNS

       • Thyroid Stimulating Hormone: Central nervous system (CNS) growth

6. Beginnings of language development

   • Language: systematic , meaningful arrangement of symbols which provides basis for comm

   • Stages of lang dev

     1. Intentional Vocalizations (first couple months)

        • Cooing - repeating sounds, vocalizations, gurgling

          1. Practice for vocalizations

          2. Vowel sounds (ooo, nanana)

        • Speaking turns - pausing in conversation, waiting for other ppl to talk

     2. Babbling and gesturing (4-6 months)

        • Babbling: Elaborate vocalizations, inc. sounds req for language

        • Gesturing: For deaf babies, use gestures for wants, reactions, feelings

          1. Rhythm and pattern of language used when deaf babies sign is same as when babies babble

     3. Understanding (10 mo)

        • Understand more than what they say

     4. Holophrastic speech (12-13 mo)

        • Partial words to convey thoughts

        • Ex: ju → for juice

     5. Underextension

        • Word for an object can only be used for that object

          1. Ex: they may the word doggie only applies for that one dog

        • over extension (more often): generalizing, think a label applies to all objects

          1. Ex: every animal is a doggie

     6. 1st words and Cultural Influences: first word differ based on culture

        • English: nouns

        • Chinese: verbs bc it verb friendly

        • May be bc diff emphasis given to objects based on culture

     7. Vocab growth spurt

        • 1 yr: 50 words

        • Toddlers: 200

     8. telegraphic speech

        • stringing minimal words together to get message across

        • Ex: doggie pretty give bby ball

• child-directed speech: exaggerating certain cowl and consonant sounds, high-pitched voice (ex: girl → GIRLIE, horsie)

  • Maybe bc this way of speaking more clearly articulates sounds or bc it’s attention grabbing

1. Gross and fine motor skill development (e.g., milestones, examples of each type of motor skill

   • Gross motor skills:Voluntary movements that use large muscle groups (typ: arm mvnt, crawling)

     • First skills developed

     • Milestones (phys skills seen in all children as they grow)

• Fine motor skills

  • Exact mvnts of feet, hands, toes, fingers (reach and grasp)

    • Real grasps start at 4 mo (tho w/o thumbs)

    • 9 mo: PINCER grip - finger and thumb PINCH

  • Dev slower bc proximodistal dev

  • Progress made in first two years

1. Piaget: Schemes, accommodation, assimilation

   • Schemes: groupings of patterns and patterns

   • Assimilation: fitting new info into existing schemas based on current knowledge/past

     • Good for relating

     • Ex: these things both have ears, tails, fur → doggie schema!

   • Accommodation: changing existing ways of thinking in response to new stimuli (we change/create new schema)

     • Ex: this cat ain’t no dog → new schema!

2. Piaget: Sensorimotor stage (born-2 years)

   • First cognitive stage

   • Intelligence based on how one experiences and senses the world

• Criticism of piaget

  • Debate on his explanations for the cause of change

1. The Strange Situation - what was measured, types of attachment and differences between types of attachment

2. Harlow’s study with infant monkeys, findings/relevance to child development

3. Object permanence

4. Language learning/development approaches

   • language acquisition device (nativist approach)

Early childhood (subject to updates as we haven’t completed this unit yet as of 9/27)

1. Types of play

   • Helps preschoolers develop!

     • American academy of pediatrics (AAP) says it is essential for the cognitive, physical, social, and emotional well-being of children and youth

     • United nations high commission for human rights

     • Maintains that play as a basic right of every child

     • These types of play are not common until the end of the preschool years

       • May be seen earlier among children with substantial social experience

   • Functional play

     • Simple, repetitive activities, typical of 3 year olds

     • May involve objects of repetitive muscular movements

       • Ex: playing with dolls, skipping, jumping, rolling, and unrolling a piece of clay

     • Doing something for the sake of being active rather than creating

     • Declines with age

   • Constructive play

     • Manipulate objects to produce or build something

     • Evident by age 4

       • Ex: building with lego or putting together a puzzle

     • Has and ultimate goal of producing something

     • Provides opportunity to test developing physical and cognitive skills and practice fine muscle movements

   • Parallel play:

     • Children play with similar toys, in a similar manner, but do not interact with each other

     • Typical during early preschool years

   • Onlooker play

     • Children simply watch others at play but do not actually participate themselves

     • May be silent of may make comments of encouragement or advice

   • Associative play:

     • 2+ children interact by sharing or borrowing toys of materials, although they do not do the same thing

   • Cooperative play

     • Children genuinely interact with one another, taking turns, playing games, or devising contests

   • Pretend play also changes during the preschool period

     • Becomes increasingly unrealistic and more imaginative - children understand/use symbols more

   • Pretend play is important to expanding cognitive skills

     • Able to practice activities that are a part of their culture

   • Play helps brain develop and become more sophisticated

     • Depriving animals of play affects the course of brain development

     • Deficiencies in the development of the prefrontal cortex (decision-making, higher order thinking)

   • Culture affects style of play

2. Erikson’s stage

   • Erikson’s psycho-social stages

     • Approximate age: what we’re most concerned about in terms of our development

       • Birth-1y - trust v mistrust

       • 1-3y - autonomy v shame and doubt

       • 3-6y - initiative v guilt

       • 6-11y - industry v inferiority

       • Adolescence - identity v role confusion

   • Psychosocial development (erikson’s autonomy vs shame and doubt)

     • Changes in the understandings of self as members of society/a large collective

     • Changes in their comprehension of the meaning of others’s behavior

   • Erikson’s stages: initiative vs. guilt stage

     • Children 3-6 years experience conflict between wanting independence and consequences of actions

     • Want to do things on their own, but feel guilty when they fail

   • Sense of self - resolving conflicts

     • Parents who react positively can help c hildren resolve the opposing feelings

     • Parents who are supportive of them being independent (is really important at this age)

     • Providing children with opportunities to act independently, while giving direction and guidance supports children, while giving direction and guidance supports children/their sense of initiative

     • Discouraging a child’s efforts contributes to sense of guild and affects self concept

   • Thinking about the self:

     • Self concept: out identity or set of beliefs about who we are as a person

       • Statements from children describing their own self concepts are not necessarily accurate

         1. They overestimate their own skills/abilities and knowledge

     • Reflects culture:

       • Collectivistic: promotes interdependence

         1. Tend to regard themselves as parts of a larger social network, where they are interconnected with and responsible to/for others

       • Individualistic: emphasizes personal identity, uniqueness

         1. See themselves as self-contained and autonomous

         2. Children focus on what sets them apart from others

3. Physical development (brain growth, weight and height gains, etc)

   • The growing brain:

     • Brain grows at a faster rate than any other part of the body

       • At age 2, brain is ¾ of adult size/weight

       • By age 5, brain is 90% of adult weight

         1. Body is only 30% of adult weight

     • Myelin: protective, insulative coating around axons of neurons

       • Increases and speeds neural transmission

     • Corpus callosum:

       • Fibers connecting the left and right hemispheres, significant growth during this period

     • Dopamine neurotransmitters increase substantially in the 3 to 6 year age period, reward and motor movement

     • From 3-6 years, the most rapid growth is seen in the frontal lobe

     • Age 6 through puberty, more rapid growth takes place in the temporal and patient lobes

     • Density of synapses (connections) peaks at ~4 years of age

     • True episodic memory may begin at this point

     • Prefrontal cortex: extensive development from 3-6 years of age, through mid-20s

4. Parenting styles

   • Effective parenting, teaching desired behavior: how well a parent responds to a child's needs and also how much a parent demands of a child (parents fall into 4 categories)

     • Authoritarian parents

       • Parents who are controlling, punitive, rigid, and cold

       • Value strict, unquestioning obedience from their children and do not tolerate expressions of disagreement

       • Research finds: children of authoritarian parents tend to be withdrawn, can be incredibly dependent of hostile

     • Permissive parents:

       • Parents who provide lax and inconsistent feedback

       • Have inconsistent expectations for children

         1. Sometimes they are reality laid back, other times they are more strict

       • Research finds: children of permissive parents tend to be dependent and more difficulty with social connections and self regulating

     • Authoritative parents:

       • Parents who are firm, setting clear and consistent limits, but try to reason with their parents

       • Explain why they should behave in particular way

       • Research finds: children of authoritarian parents, generally independent, friendly, self-assertive, cooperative, motivated to achieve, able to regulate their own behavior

         1. Some authoritative parents display supportive parenting. Parental warmth, proactive teaching, calm discussion, and interest in involvement

     • Uninvolved parents:

       • Parents who show virtually no interest in their children, displaying indifferent, rejecting behavior

       • In it's most extreme form, it results in neglect

       • Research finds: children of uninvolved parents tend to have disrupted emotional development; impedes physical and cognitive development

5. Gross and fine motor skill development (e.g., milestones, examples of each type of motor skill)

   • Gross motor skills:

     • By 3 years old, children have mastered a lot of gross motor skills:

       • Jumping

       • Hopping on one foot

       • Skipping

       • Running

     • By 4 they can throw a ball with enough accuracy for someone to catch it

     • By 5 they can play ring-toss or mini basketball

     • Why do they advance as we get older?

     • Partly because of changes to skeletal system (like we saw in babies video)

     • And partly because of practice…

• Fine motor skills:

  • At age 3, children can:

    • Put together a simple puzzle

    • Fit blocks into matching holes

  • By age 4, they can:

    • Fold a paper into triangular designs

    • Print their name with a crayon

  • By age 5, they can hold and manipulate a pencil

1. Conservation: the quantity is unrelated to the arrangement and physical appearance of objects

   • Kids cant take into account the multiple aspects of a situation

   • Results from centration - young children cannot focus on multiple aspects of a situation, takes things at “face value”

2. Egocentrism during preoperational stage (piaget)

   • This kid is so self centered

   • Thinking does not usually take the viewpoints of others into account

     • Lack of awareness that others see things from a different physical perspective

     • Failure to realize that others may hold thoughts, feelings, and points of view that are different

   • At the heart of several behaviors in children

     • Talking to themselves

     • Ignoring what others tell them

     • Being bas at hide and seek

   • Strengths:

     • Useful wat of thinking about progressive advances in cognitive ability

     • Insightful and groundbreaking, for that time

   • Weaknesses:

     • Observations of relatively few children

     • Underestimated children’s capabilities

     • Stage theory

     • Children can be taught to answer correctly on conservation tasks

     • Focuses on deficiencies in thinking

3. Vygotsky - learning, scaffolding

Learning:

• Cognitive development: a result of social interactions

• Children learn through guided participation

• Children gradually grow intellectually and begin to function on their own because of assistance provided by partners

• Contended that the nature of partnership between developing children and adults/peers is determined largely by cultural and societal factors

  • Culture and society established institutions that promote development

• Culture and society emphasize particular tasks

  • Toys

  • Gender roles

Scaffolding:

• Zone of proximal development (ZPD)

  • Level at which a child can almost, but not fully, comprehend or perform a task without assistance

  • Scaffolding: support for learning and problem-solving that encourages independence and growth

    • Includes cultural tools -- actual, physical items, as well as and intellectual and conceptual framework for solving problems

      • Pencils, paper, calculators, computers, language, alphabetical and number systems, mathematical and scientific systems, religion, etc.