Developmental psych1/8/13 5:00 PMLife Span PerspectiveScientific study of how people change over the life spanEmphasizes continuity over the life span Developmental change is not discreet Development is life long

Developmental ChangeMulti-directionalSome things are gained, others are lostGrowth, Maintenance, Regulation of LossMulti-contextualMany different factors affect changeGenes, environment, culture, etcMulti-disciplinaryChange occurs in many waysNeurology, learning, intelligence, social, culturalPlasticityChange can occur at any time.to varying degrees

Nature Vs. Nurture debateClassical philosophy: rationalism vs. empiricismGreek Rationalism: Plato, true knowledge attained only through introspection, reason and innate ideasBritish Empiricism: John Locke, blank slate, all ideas come from sensesModern Rationalism: GeneticsModern Empiricism: Behaviorism, learning theoryNATURE AND NURTURE, its both.Developmental Psych1/8/13 5:00 PM

1/8/13 5:00 PM

Heredity and ChromosomesEach egg and each sperm contain 23 chromosomesFertilization: sperm and egg combineEmbryo has 46 chromosomesDefines the childs heredityIncluding sex and other physical traits

Chromosomal AbnormalitiesDown SyndromeTrisomy 21: An extra copy of chromosome 21 (have 3 instead of 2)Facial deformities, delayed motor and mental abilitiesIncreased risk with age of motherKlinefelter SyndromeMales have extra X chromosome (XXY instead of XY)Undeveloped testes and some feminine features (including breasts)Fragile X SyndromeDamaged X chromosomeDelayed or reduced mental abilitiesTurner SyndromeFemales missing one of X chromosomesSome of physical deformity, infertility, and some mental retardationXYY SyndromeMales with an extra Y chromosomesSlight increases in physical growth rateSlight delays in language development

What Genes DoRegulate protein productionBuilding blocks of all cells/tissue in the bodyGenotype: a persons genetic makeupPhenotype: a persons actual featuresDominant vs. recessive genesIndividuals not the sole product of their genesEpigenetics: complex interactions between genes and environment

EpigeneticsPassive genotype-environment interactionBiological parents provide the rearing environmentEx: parents provide a genetic basis for intelligence as well as encouraging intellectual developmentEvocative genotype-environment interactionChilds genotype elicits particular environmentsEx: Smiling babies elicit more social interaction, reinforcing extrovert behaviorActive genotype-environment interactionNiche-pickingEx: Good sensorimotor skills may lead child to play sports >> in turn improves sensorimotor skills.

What is inherited?Physical traitsHeight, weight, hair color, skin color, eye color, blood type, many misc. physical featuresEnvironment still plays a role in phenotype of these traitsEg nutrition/diet + genes >>height & weightPsychological traitsBehavioral genetics= study of the contributions of genes and environment to psychological traits

Nature Vs. NurtureIntelligenceFamily resemblance is insufficient to say its all genesEx: parents are intelligent, so are children, so does it mean IQ is inherited?Environment could just as likely have caused the intelligenceIntelligent parents encourage children to participate in intelligent activities

Twin StudiesTwinsMonozygotic= identical twinsExact same genotypeDizygotic= fraternal twins (non identical)Different genotypeCompare psych. Similarities between mono and diz twinsTwins experience same environmentOnly difference is genotypeIf mono twins are more similar then the genotype must play a strong role in the traitIf diz twins are just as similar as mono twins environment must be the factorEX DEPRESSIONIdentical twins: if one twin is depressed- 75% chance the other one will beFraternal twins: if one twin is depressed- 25% chance the other one will be depressedAdoption StudiesChildren raised by adoptive parentsIf the children share psych traits with biological parents >> genetic basis for these traitsMono twins raised in separate households:If similar psych traits >> genetic basis for these traitsConversely, if adopted children are more like their adoptive parents >> environmental basis for these traitsSeparated at BirthJim and Jim twinsSeparated at 4 wks, reunited at age 39Similarities:Were part time sheriffsVacationed in floridaMarried and divorced women named bettyHad dog named toyChewed nailsSons had same nameHad headachesTwo female identical twinsSeparated at 6wksReunited in their 50sSimilarities Identical nightmaresImages of doorknobs and fish hooks in mouths and smotheringBedwetters until they were 13

PRENATAL DEVELOPMENT

CONCEPTIONSperm 23 chromosomes + egg 23 chromosomesFertilization occurs in fallopian tubeThe Germinal period: 1st 2 weeksAKA period of the zygoteZygote = fertilized eggInitially single cellRepeated processes of cell divisionNumber of cells increases at exponential rateMono twins can occur at this stageCells are all identical early in the germinal periodPUT PICTURE HERE

EMBRYONIC STAGEAka period of the embryoCells become more specializedBody structuresInternal organsBeginning of embryonic stageThree layers form in embryoEctoderm: outer layerWill become hair, skin and nervous systemMesoderm: middle layerWill become muscles, bones, circulatory systemEndoderm: inner layerDigestive systemCephalocaudal principleHead develops before rest of bodyMore rapidlyEarly stages: head is 50% of body lengthAt birth head is 30% of body lengthEctodermEarly in third week a fold appears = neural tubeWill become the CNSNeural TubeMantle Layer- source of differentiating cellsCells will become important parts of CNSNeural tube defectsCritical stage of developmentCertain complications can ariseResulting in neurological problems in child (or worse)

Neural Tube DefectsFrequency 6-8 per 10,000 births in USSharp decline in last 20 yearsAttributed to early detection and abortion, and improved nutritionSome causesGeneticsDrugs (esp psychotropic taken by mother)AnencephalyHead regions of neural tube fail to closeCerebral hemispheres fail to develop no cortex at birthInfant cannot surviveSpina BifidaSpinal cord area of neural tube fails to closeGrowth of exposed spinal cordParalysis commonIntellectual development frequently impairedSurgery usually required to protect exposed spinal cord

Ectoderm4th weekbrain region closes inmajor neuron generationhead area enlarges limb buds form5th weekfunctional nervous systembrain wave activity presentreflexive movement in response to touch

FETAL STAGE: weeks 9-38 (birth)Aka period of the fetusEnd of first trimester + 2nd and 3rd trimestersMajor growth in all body organsWeeks 17-20Fetus can moveGrowth of temporary body hair = lanugoSkin coated with protective substance = vernixThird trimesterAge of viability = 22 weeksFetus can now survive on ownSpecialized medical care still requiredEnlargement of cerebral cortex

TeratogensSubstances or environmental conditions that can impair prenatal developmentBehavioral teratogens those that specifically impact CNS and affect a childs later developmentEx:Thalidomide (sleeping meds known to cause deformatins of arms and legs) and other prescriptionsLegal and illegal drugsTobacco: low birth weightAlcohol: fetal alcohol syndromeCocaine, heroine: addiction, mortality risk, premature birthRubella: if contracted by mother can cause blindness and or deafness in childSome diseases can be transmitted to the child (HIV, hepatitis)Environmental hazardsFASSyndrome due to maternal alcohol abuseDue to binge drinking or regular heavy drinking, esp early in pregnancyAbnormal facial characteristics, impaired learning, motor coordination, problem solvingFetal alcohol effects: even small amounts of drinking during pregnancy can lead to behavioral changesMothers who reported drinking only 1x per week were 3x more likely to have children with : Clinical aggressionDelinquencyAttention deficitCritical/Sensitive periodExtent of effect of a specific teratogen depends on stage of development3-8 weeks highly sensitive to teratogens

RANDOM SHIT with fetal healthNutritionEg folic acid helps developing nervous systemPhysical growth and proper birth weightMaternal stressAssociated with increased likelihood of miscarriage, prematurity, and low birth weightMaternal ageEg down syndrome risk

BIRTH

Labor thought to be triggered by a signal from fetal brain that monitors development of body organs and systems. Three stages to laborStage one: uterine contractionsCan last 12-14 hours the first timeWeak, irregularly spacedCervix begins to dilateEnd of stage onereported as most painful stage >> contractions intensify, cervix dilates to 10cm or 4 inStage two: pushingFeel urge to pushCrowning occursnormal birth- baby comes out head firstBaby is bornStage three: afterbirthPlacenta is expelled from the uterusAssessing NewbornAPGAR scale5 vital signs are measured to assess newborns condition, scored 0-2 points each10 point scale:7-10 good, 4-6 some vital signs are low, > synaptogenesisLearning shapes these patternsStrengthens some connectionsEliminates others

Brain Growth in InfancyBorn with nearly all neurons you will ever have = 100 billion Development = forming connectionsActivity dependent learning/experienceFirst few monthsAxons and dendrites grow longer# of synapses increase2nd year synaptic pruningsome synapses disappearfine tuning brain functionweeding out unnecessary connections

Brain Function and PlasticityBrain must change to learn and acquire new behaviorsDamage results I lost behaviorBehavior can be recoveredNeuroplasticityBrain can change in functionLost functions can be taken up in other parts of the brainOld view on neuroplasticityEnds in childhoodBrain set in stone by adulthoodNew viewPlasticity never endsBrain is just more plastic in early childhood compared to adulthood

Movement and Motor SkillsNo real motor controlMovements are not voluntary and controlledSome movements are random and uncontrolledSome movements are involuntary reflexesStartle reflexes aka moro reflex disappears around 5monthsTonic neck reflexSuckingRootingPalmar/graspingCrawling/swimmingSteppingBabinski reflex

Gross Motor SkillsControl of large limbsArms and legsWalkingMust overcome cephalocaudal-driven development8months stand with help9months stand while holding onto something10months stand alone12months walk alonewhat determine this developmental trajectory?Genes vs practice/exerciseComplex task involving integration of many subsystemsPosture and balanceStepping and limb controlVisionCoordinating all of thisDynamical systems theoryBehavior arises out of a self-organizing systemWalking as a natural consequence of all these basic subsystems coming onlineReaching4months- successful reachingstill clumsymany submovementspast 4monthsgradual smoothing in movements

Fine Motor SkillsReaching and graspingRequires direction and distance perceptionInfants 6-11 daysRough accuracyInfants will not reach for things out of reach distanceUp to 4monthsImprovement in directional accuracyCan intercept moving objectsSharpening of line between reachable and non reachable distances

PerceptionChemical senses: tastes and smellTaste is fairly well developed at birthInfants sensitive to all 5 primary tastes: sweet, sour, salty, biter, umamiTaste preferencesDifferent responses to different tastesChange in nursing behaviorSmell is fairly well developed at birthInfants respond to different smellsDistinguish and prefer own mothers breast milkPlace head between two padsPad on one side has mothers milkOther pad has different womans milkChild turns head toward mothers milkTouch: moderately developed at birthTouch required to elicit reflexesInfants respond to soothing and caress, body heatBabies are born with touch mechanoreceptors in the skinReceptors for pressure, movement, pain, temperatureDevelopment involves increase in touch pattern recognitionDevelop ability to perceive posture and movementProprioception and kinesthesis via receptors embedded in muscles, tendons and jointsHearing: not well developed at birthFetus can hear sounds-7-8 monthsinfants can hear but not as well as adultsreceptors in inner ear are developed but connections need to forminfants have higher threshold for hearing a sound (less sensitive to quiet sounds)testing hearing in infantsbaby sits on parents lap and observed from another roombaby wears headphonesexperimenter plays tones over headphonesparent and observer wear headphones with silence observer codes when they think the baby is attentivechange in facial expression or head orientationmatch attentive times with actual times a tone was playedscreening new borns for hearing lossauditory brainstem response (ABR)electrodes detect activity of auditory nerve in response to soundsotoaccoustic emissions (OAE)probe in outer ear detects echo responses from the receptors in the inner earadults can locate sound sources, but can infants?In dark the experimenter shakes a rattleSee which way the infant reaches and how far they reach7months old they will not reach a rattle sound more than 2 feet away.PerceptionVision: poorly developed at birthInfants: poor acuity and sensitivityAcuity: how well can you see fine detail?Sensitivity: how well can you detect faint visual stimulusAdult normal vision: 20/20Can see at 20 ft what an average person sees at 20 ftInfant 1mo: 20/400Can see at 20 ft what an adult sees at 400ft6mo: 20/10012mo: 20/4036mo: 20/20Visual testing methodsPreferential lookingAssumption: child will prefer looking at a pattern vs a uniform gray fieldShow child two gratingsCan child see difference?If not then no difference in looking time between the 2 stimuliIf yes then more time spent looking at low freq gratingVisually evoked potential (vep)Electrodes on scalp, measure brain activity in visual cortexPresent high and low freq grating or checkerboard patternCan child detect differenceIs VEP activity different between the two gratings?If yes child detects differenceIf no child cannot tell differenceOptokinetic nystagmus (OKN)Move grating laterally; eyes reflexively follow the gratingIn infants: if they can see the lines, will exhibit OKN reflex

Cognitive developmentPIAGETChild as nave scientistUnderstanding physical world and how to interact with itSchema: a nave theory about how the world worksChildren test their theories by playing and doing thingsAssimilation: new info incorporated into schemaAccommodation: change schema to accept new info inconsistent4 stages: sensorimotor, preoperational thought, concrete operational thought, formal operational thoughtsensorimotorgradually learning about bodyhow to interact with objectsproperties of objectsgravity/supportsoliditycontainmentpermanenceLanguage developmentCan infants recognize language sounds?Infants prefer mothers voice over a strangersCan they discriminate speech sounds?Habituation techniquesRepeatedly present same stimulusChild gets used to itChange stimulusIf child detects changes make a responseIf no change detected make no responseLanguage perception studyPacifier outfitted with electronic monitorEach time child sucks, activates a bah sound played through headphonesChild initially sucks rapidly but then gets bored and slows downSound is switched to gah and child habituatesHappens as young as 1monthSpeech perceptionThere are 140 phonemesBasic sounds of language that could be used in any languageMost languages use about 301month old can distinguish between all 14010month olds will only dishabituate to the phonemesused in the language they are exposed toex a French exposed child will notice the difference in nasalization of vowels but an English exposed child will notchild directed speechspeech by adults to childrenslow exaggerated changes in pitch and loudnesshelps children hear phonemes and learn languagemust learn to coordinate the articulatorscooing: vowel sound by 2monthsbabbling: consonant sound by 6monthsintonation: patterns while babbling by 7monthsfirst word by 12monthsholophrase: single word sentence by 12-15 monthsnaming explosion: acquire 50-100 words per month by 18monthsgrammar acquisitionconstructing larger sentencesuse articles and function wordsmorphologytelegraphic speech: simplified sentences: 2 yearskick ballfluent speech: full grammatical speech by 5 yearsI am kicking the ballTheories of language acquisitionBehavior approach (strong nurture)Skinner: babbling and language use is reinforcedLanguage is essentially mindless imitationCognitive approach (moderate nurture)Semantic bootstrapping: children hear grammatical language and infer the rules of languageNativist approachChomsky: innate language acquisition device encodes grammar into the brainUniversal grammatical structuresBrain structures specific to languageLanguage specific to humansPoverty of stimulus argument: children do not hear enough language to explain the early complexity of their languageDegeneracy of stimulus argument: children hear both correct and incorrect grammar and are still able to learn a language