3011PSY Lifespan Dev - Week 2 (Prenatal and Early Development)

Maternal Age

30-40years + -Infertility -Miscarriage -Chromosomal defects 50-55 years + dramatic increases with risk Teenagers also show high risk but more so because they are more likely to be low SES

Australian NHMRC Guidelines re: alcohol and pregnancy

"A 'no-effect' level has not been established, and limitations in the available evidence make it impossible to set a 'safe' or 'no-risk' drinking level for women to avoid harm to their unborn children, although the risks to the fetus from low-level drinking (such as 1 or 2 drinks per week) during pregnancy are likely to be low. A conservative, public health approach has therefore been taken in recommending that 'not drinking alcohol is the safest option' for pregnant women and women planning a pregnancy." (p. 68)

Gene and environment conclusion

-Genes -Early environment -Interaction between the two -And timing of interaction between the two Place us on a developmental pathway that influences the rest of our development

Speech Perception

1 month: differentiate phonemes /p/ from /b/ (Eimas et al., 1971) Phonemic discrimination initially universal From 6 - 8 months screen out non-native sounds By 9 months: only discriminate native language phonemes Between 6-8 months babies screen out sounds not used in native language.Prefer hearing human speech over nonword sounds, or native lanaguage over foreign.

Child body size

1 year= 32 inces (50% more than birth) 2 years= 36 inches (75% more) 5 months birth weight doubled to 15lbs 1 year weight has tripled 2 years weight has quadrupled to 30lbs. Growth is not steady but dramatic Eg. Over the first 21 months they will not grow for 7-63 days then grow as much as half an inch within 24hrs. This is seen in the round plump baby at around 9months.

Teratogens Risk Factors

1. Heredity e.g., alcohol dehydrogenase gene 2. Interaction effects e.g., alcohol + marijuana, no safe thresholds 3. Timing sensitive and critical periods 4. Dose: generally larger dose over longer time = more damage 5. Age: Sensitive period of development 6. Poor nutrition: May be safe thresholds Example: alcohol WHO recommends no known safe level of alcohol during pregnancy Australian NHMRC Guidelines -safest = no alcohol during pregnancy or breastfeeding All of these risk factors are exaggerated when in a low SES environment!!!

How alcohol affects child

1. Interfers with production and migration of neurons in primitive tube. 2. Body uses large amounts of oxygen to metabolise alcohol, which draws oxygen from the child's developing cell.

Development of neurons

1. Prenatal period: -Neurons produces in primitive tube -Migrate to parts of brain and differentiate their unique functions by connecting with cells -First two years this happens at VERY fast rate -Cell death occurs to make space for these connections -Neurons need Stimulation from input to survive here and continue creating connections. -Neurons that are not stimulated lose their connections (Synapse pruning, 40% are pruned to reach adulthood) 2. After prenatal period -Few new neurons are created after prenatal -But brain grows due to Glial Cells coating neurons with Myelin. (Myelin is 30% of brain at birth and 70% of brain at adulthood)

Fetal Alcohol Syndrome (FAS)

1. Slow physical growth 2. Pattern of three facial abnormalities (Short eyelid, thin upper lip, smooth or flattened philtrum 3. Brain injur: Small head and impairment in three areas of functioning (eg, memory, learning, communication)

Partial Fetal Alcohol Syndrome (pFAS)

1. Two of the three facial abnormalities 2. Brain injury in three areas

Alcohol related neurodevelopment disorder (ARND)

3 areas of brain function is impared

Genes don't work alone

Again, due to unique genetic makeup, we respond differently to the same environments But same genes also respond differently to same environments when exposed at different periods of development

Infant Brain Development

All major brain developments happen within first 2 years. Then another major development in adolescence. But continues ti develop through life. At birth birth: 25% adult brain weight 2 years: 80% Increases due to dendrite growth and myelination 5 fold increase in dendritic density by 2 years

Emotional Stress

Anxiety, especially in first 2 trimesters: -Miscarriage -Low weight -prematurity -colic -sleep issues respiratory issues Caused by release of stress hormones cortisol and epinephrine. Blood is moved to limbs and away from child, less nutrients and oxygen to child.

Statistical learning capacity

Babies locate regularities in language. Listen for syllables that belong together. Baby boy Ba-by by-boy

Regions of cerebral cortex

Because its the last area to develop it is sensitive to environmental influences for longer. The order the cotex developems is dictated by the childs needs Eg. -First year sees auditory and visual cortexes and body movement activity. -Language areas are active from late infancy through to preschool years Prefrontal lobes have the most extended periods of development, thought, consciousness, impulse control, memory use, reasoning, judgement, problem solving. -Is actove from 2 months onwards, but see most myelination and pruning in school years.

Changes in body perportions

Cephalocaudal Trent: -First phase -Head develops more than rest of body Proximodistal trend: -Limbs develop 1 Head, chest and truck 2 Arms and legs 3 Hands and feet

Gibsons differentiation theory

Children actively search for invariant features of the environment, those that remain stable, in a constantly changing perceptual world.

Infectious disease: Bacterial and parasitic

Chlamydia Syphilis Tuberculosis Malaria Toxoplasmosis (from eating raw or uncooked mate or coming in contact with animal faeces. Causes eye and brain damage

Illegal drugs: Cocaine, Heroin, Marijuana

Cocaine and heroine: Addicted babies, withdrals, Premature, low birth weight, physical defects, breathing difficulties, death around birth. Cocaine: Alters production and function of neurons and creates chemical imbalances. Resulting in retardation, eye, bone, genital, urinary, kidney and heart defects. Also motor, attention, memory and impulse control issues. Some other studies do not find any negative effects of cocaine use Marijuana: Linked to smaller head, attention, memory and academic achievement. Impassivity, over activity, depression and anger in adolescence and childhood.

Learning Objectives

Critical and sensitive periods Impact of teratogens on development with specific reference to alcohol How & why the brain develops during infancy & implications for other skills Research methodology for studying infant development How infant perception develops

Critical and sensitive periods

Critical period: -maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli -Limited time span eg. Poor nutrition leads to lower IQ Sensitive period: -window of opportunity where experiences have a greater impact on certain areas of brain development -Less defined periods than critical eg. learning a language first 2 years

Toddler imitation

Depends on motor and cognitive skills necessary to carry out the action to be imitated. At 15 months, children this age are usually mobile and have some hand-eye coordination. https://www.youtube.com/watch?v=yECd_Sz_zJ8

Depth perception

Depth Perception: -Ability to judge distance of objects -Tied to motor development, esp. crawling -the Visual Cliff -We use visual cliff experiment to understand baby's behaviour -Motion is first depth cue to which infants are sensative. Using binocular depth with our two eyes around 2-3 months. -Pictoral depth cues are initialed at 3-4 months, similar to how artists create depth (receding lines, overlapping objects, and shadows. Babies use depth cues to detect danger of falling. Crawling strengthens childs memory of locations and things

Two types of brain development

Experience-expectant brain growth: -Brain depends on ordinary experiences to devleop and grow. Human interaction, environmental exploration, hearing language Experience-dependent brain growth: -Occurs throughout our life. Specific learning experiences across individual and cultures. The first lays the foundation for the second. No evidence for the first 5-6 years as crucial to learn any skill (musical, athletic etc). Rather is can be harmful by 'rushing early learning' and overwhelming the brain and its neural networks, thereby reducing the brains sensitivity to everyday experiences.

Face perception

From 3 months infants descriminate between faces: preference for mother's face. and female over male face. Used to researchers' advantage in "still face" experiments. Prefer to see faces in photos and simplified drawings with natural features, rather than different angels and upside down. The also prefer to track a face in their visual field than another object. They prefer faces with eyes open and direct gaze. Also prefer attractive faces, and their own race.

Understanding perceptual development

Gibsons differentiation theory Children actively search for invariant features of the environment, those that remain stable, in a constantly changing perceptual world. In pattern recognition for example: Babies search for features that stand out and orient toward faces. Soon they explore stimulus, noticing stable relationships among features. as a resulte they detect patterns such as complex designs and individual faces. They also analyse speech streams for regularities, detecting words, word order sequence.

Habituation

Gradual reduction of the strength of a response due to repetitive stimulation. 'Recovery'- Change in environment cauases responsivness to return to high level Infants rely on habituation and recovery more than any other learning style. Babies recover to a familiar stimulus rather than a novel stimulus. Eg: When you return to a place you haven't seen for a while you focus on the familiar things not the novel things

Perceptual Development

Hearing -Well developed at birth -Preferences for: -mother's voice over stranger -"baby talk" over "adult talk" -mother singing over speaking -native language over non-native language

Tobacco

Increases in low birth weight, miscarriage, prematurity, clef lip and palate, impaired heart rate and breathing during sleep, infant death, cancer, and asthma. Nicotine restrics blood vessels and lessens blood flow to uterus, reduces nutrients sent to child.

Imitation

Infants 2-3 months imitation is harder to induce than newborns babaies. So some thing it is simply an automatic response. Others belive that babies will imitate long after the adult has done the behaviour. Brain imaging supports mirror neurons as early as 6 months old in cerebral cortex

Intermodal perception

Intermodal perception is the perception of an object or event that makes information available to two or more sensory systems simultaneously. Most objects and events are multimodal in that they can be experienced through multiple sense modalities. OR Perceving things and integrated wholes (if we touch it, it doenst change what it is. A baby will just need to hold a ball to know it is separate from everything else and is its own object. They also use sounds to strengthen this: Eg: mothers face and sound of voice.

Lateralization and plasticity of cortex

Lateralization: the specialization of the two hemispheres in the brain Left= verbal abilities and positive emotion -Better at processing info in sequential, analytic way Right= spacial abilities and negative emotion -Better at processing info in holistic, integrated manner Plasticity= areas of brain that are not yet committed to specific functions, high capacity for learning. If some parts are damaged other parts can take over. But once lateralization occurs this is made harder to compensate for.

Infant Development: learning

Learning: changes in behaviour as a result of experience Infants learn through: -classical & operant conditioning -observational learning -imitation -habituation & recovery Mirror neurons - fire identically when observing a behaviour as when performing behaviours

Environmental Pollustion

Mercury from fish and chemicals PCBs used to insulate electrical equipment entered waterways, resulting in low birth weight, discolored skin, deformed gums and nails, cognitive dev issues, brain wave issues, lower IQ Lead from paint, low borth weight, brain damage, mental and motor issues. Dioxins, toxic compounds fro incineration. Leads to breast and uterine cancer.

Chnaging states of arounsal

Newborn takes naps at around 16-18hours, total sleep times declines slowly. Average 2yr old still needs 12-13hrs. Most 6-9 months old take 2 day naps, by 18 monthsy only 1 nap. 3-5 years naps are gone. Dutch babies sleep 2hrs more per day than US babies, because it is more impartant to the Dutch. Melatonin isnt produced until 6months.

Environment

Poverty Associated with: -Increased stress -Fewer but more hostile interactions -External environmental risks -Serious developmental risks

Fetal Alcohol Spectrum Disorders (FASD)

Result from exposure to alcohol (again a teratogen) 1 - 3 per day: ARND (Alcohol-related Neurodevelopmental Disorder) or Fetal Alcohol Effects > 3 per day or binging (5+) in early pregnancy: 'Fetal Alcohol Syndrome' But even less than one drink a day is associated with reduces head size and body growth.

Rh Factor Incompatibility

Rh incompatibility is a condition that develops when a pregnant woman has Rh-negative blood and the baby in her womb has Rh-positive blood. Can reduce oxygen supply to organ and tissues due to antibodies.

Nutrition folic acid

Taking Folic acid around conception reduces more than 70% of abnormalities in neural tube, such as spina bifida also clef lip, urinary abnormalities, limb deformities. During last 10 weeks it reduces risk of low borth weight

Prenatal Development: Critical Periods and Teratogens

Teratogens: harmful environmental agents/conditions that impair prenatal development and lead to death, birth defects, or later emotional, behavioural, and/or intellectual impairments Key stages of prenatal period, harms fetus in different ways Most harmful during embryonic period. Least harmful during fetal period Teratogens Examples -Prescription on drugs -Illegal drugs -Environmental hazards -Parental factors Some teratogen damage is not immediate, it may show up later in life. Eg. mothers drug use may affects the child's ability to explore the environment leading to social issues later in life.

Prescription drugs: Thalidomide, diethylstilbestrol, vitamin A, asprin, Caffeine, antidepressnats

Thalidomide Sedative drug , when take 4-6 weeks after conceptions produced gross deformities of the embryo arms and legs, lower IQ, etc diethylstilbestrol Used to prevent miscarriages, caused vaginal and testical cancer, infertility, uterus malformations. Vitamin A Used as an ache treatment, results in eye, ear, skull, brain, heart and immune issues. Asprin Linked to low birth weight, infant death, poor moter development, lower IQ scores Caffeine Low birth rate Antidepressants Birth complications Anything with molecules small enough to cross the placental barrier

Expression of FAS depends on...

Timing of alcohol consumption relative to the stage of fetal development -Incl. exposure prior to pregnancy, incl. by father -Most vulnerable between 3 - 6 weeks Dose and frequency of consumption Socio-behavioural risk factors (maternal age/duration of drinking, low SES, race, genetic differences, polydrug use)

Classical conditioning

Unconditioned stimulus paired with a reflexive of conditioned stimulus. This creates neural connection in babies brain. EG: -Breast milk UCS resulted in sucking UCR (operant) -The neutral stimulus of head stroking presented just before or at the time of the milk (UCS) creates a connection between head stroking a sucking (Classical) Extinction occurs if head stroking happens without the milk enough times Fear is hard to condition in newborns until motor skills develop..

Infectious disease

Viruses Bacterial Parasitic

Infectious disease: Viruses

Viruses: Rubella: Fetal and newborn deaths. If during embryotic period: deafness, eye deformities, heart, genital, urinary, intestinal, bone and dental defects. Retardation. Less harmful during fetal period, low weight, hearing loss, bone defects. HIV leads to AIDS. In south Africa 30% of pregnant women are HIV positive. 20-30% pass it to their child, of which nearly half die before 1 year old. Antiretrovol drugs decrease transmission by 95% with no side effects. Also: Chicken pox Herpes Mumps

Vision

Vision (least well developed at birth) Visual acuity: birth 20/120 By around 6 months 20/80 Adult 20/20 by about 4 years Prefer mothers face over strangers At 6 months they prefer female over males face

Vision preferences

Vision Preferences 3D movement colour complexity curves symmetry (Fantz, 1963)

Operant conditioning

Works on the stimuli that follows child's own behaviour. Stimuli that increases behaviour is a "Reinforcer" The opposite is a "punishment" Will suck faster if produces more interesting sounds and sights. Great for finding out what babies prefer.

Teratogens

harmful environmental agents/conditions that impair prenatal development and lead to death, birth defects, or later emotional, behavioural, and/or intellectual impairments EXAMPLES: Prescription drugs: thalidomide, accutane (Vitamin A) Illegal drugs: marijuana, cocaine, alcohol and tobacco Environmental hazards: X-rays, pollution disease: Rubella, HIV/AIDS, STDs Parental factors: maternal malnutrition, stress, age; paternal age, Vitamin C deficiency, exposure to toxins, smoking

Determinants of brain development

maturation + stimulation Deprivation studies -e.g., Rozenweig's (1984) rat experiments -Human deprivation studies (Beckett, 2006) Eg, kittends deprived to light for 3-4 days resulted in these areas of brain degenerating Eg. Children born with cataracts, if they are removed within 4-6 months sight is good, if it is postponed there are visual issues, and if they wait till adulthood they are severely impaired. Eg. Romanian children institutionalized for over 6 months showed serious intellectual deficits. Although it did improve later in life, they were still below average. They also showed lack of impulse control, inattention and autistic like behavior (caused by lack of activity in prefrontal cortex). Also the longer the children spent in the orphanage the higher their cortisol levels-even 6 years after adoption.

Contrast Sensitivity

when the contrast between objects and their background often is reduced. Driving at night is an example of an activity that requires good contrast sensitivity for safety. If babies are sensitive (can see more) to the contrast in two or more patterns, they prefer the one with more contrast.