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212 Cards in this Set

  • Front
  • Back
Child Development vs Developmental pyschology
-the study of all aspects of growth and change from conception to adolescence
-covers entire life span
Why study child development?
-practical reasons like help parents with raising children
-choosing social policies
-understandin human nature (how much do babies know when they are born?)
What are the seven enduring themes in child development
1.nature and nurture
2.the active child
3.continuity/discontinuity
4.mechanisms of developmental change
5.the sociocultural context
6.individual differences
7.research and children's welfare
Nature and Nurture
-2 issues: why are we all the same and why are we all different
-need both (intertwined); every characterisitic we posses is created through joint workings of nature and nurture
-question is how do they work together (ie critical periods in language development)
-to say one is more important than other is to oversimplify developmental process
nature
biological endowment; the genes we receive from out parents
nurture
the enviroments, both physical and social, that influence our development
The Active Child
-how do children shape their own development
-in toddlerhood have example of temperament and parenting style (difficult temperament ellicits harsh parenting which in turn changes child's environment)
-in adolescence have peer selection and peer influence (tend to take onn habits of friends but choose own friends
-children's contribution to own development increases as they grow older
Continuity vs Discontinuity
-matter of perspective
-is change gradual (continuity) or in stages (discontinuity)
-concluded that in most aspects of development changes are gradual and development occurs skill by skill, task by task rather than in broadly unified way
continuous development
-idea that changes with age occur gradually, in small increments, like that of a pine tree growing taller and taller
discontinuous development
-idea that changes with age include occasional large shifts, like the transistion from caterpillar to cocoon to butterfly
-start from common observation that children seem qualitatively different at different ages
stage theories
-approaches that propose that development involves a series of discontinuous, age-related phases
-entry into new stage involves relatively sudden, qualitative changes from one coherent way of experiencing world to a different coherent way of experiencing it
-children of given age show broad similiarities across many situations and children of different ages behave very differentyl
Mechanisms of Change
-how does cognitive development happen? (beyond nature and nurture which determine what changes occur and when)
-speed of processing improves via maturation
-strategies learned from experience (ie arthmetic strategies)
-content knowledge from experience
The Sociocultural Context
-how does culture influence development?
-compare lives of children who grow up in different cultures to understand influence of sociocultural context
-in modern multicultural societies many contextual differences are related to ethnicity, race, and socioeconomic status
sociocultural context
-the physical, social, cultural, economic, and historical circumstances that make up any child's environment
-influences every aspect of children's development
Parts of the sociocultural context
-ppl interact with
-physical environmnet in which child lives
-institutions that influence children's lives
-general characteristics of the child's society
socioeconomic status
-a measure of social class based on income and education
-SES
-exerts a particularly large influence on children's lives
What three characteristics do the resilient children that overcome poverty have?
-positive personal qualities such as high intelligence, easygoing personality
-close relationship with at least one parent
-close relationship with at least one adult other than their parents
Individual Differences
-why are we all different
-what causes these differences
-different effects of same experience
-environmental differences can be cause by genetic differences (active child)
Four factors that cause individual differences
-genetic differences
-differences in treatment by parents and others (environmental differences)
-differences in reactions to similiar environments
-different choices of environments (active child)
Research and Children's Welfare
-applying research (ie critical perionds in language and vision, if diagnose early can be corrected easily)
-public policy (ie education and curriculum)
Three contexts for gathering data
-interviews
-naturalistic observation
-structured observation
Interviews
-children answer questions asked either in person or on a questionnaire
-use in clinical situation (depression, affect of divorce) -sense of the subjective experience
Advantages of Interviews
-reveal subjective experiences (flexibility)
-structured interviews are inexpensive and give in-depth information about individuals
-clinical interviews allow for flexibility for following up unexpected comments
Disadvantages of Interviews
-answers are often bias to reflect favorably on interviewee
-memory of interviewee often inaccurate and incomplete
-prediction of future behavior is often inaccurate (hard to generalize)
Structured Interview
-all participants are asked to answer the same questions
-have set of question prepared
-useful when goal is to collect self-reports on the same topics from all of the ppl being studied
Clinical Interview
-questions are adjusted in accord with the answers the interviewee provides
Naturalistic Observation
-examination of how children behave in their usual environments
-observer is unobtrusive in background so as not to influence behavior
-best with social interactions that are frequent (ie family dynamics)
Advantages of Naturalistic Observation
-useful in describing behavior in everyday settings
-helps illuminate social interactin processess
Disadvantages of Naturalistic Observation
-difficult to know which aspects of situation are most influential
-limited value for studying infrequent behavior
Structured Observation
-present identical situation to each child and record each child's behavior
-same situation for all
-can have behavior that is infrequents
Advantages of Structured Observation
-ensures that all children's behaviors are observed in the same context
-allows controlled comparisons of children's behavior in different situations
Disadvantages of Structural Observation
-context is less naturalistic than in naturalistic observation
-reveals less about subjective experience than interviews
Variables
-attributes that vary across individuals and situations such as age, gender, and experiences
Correlational Design
-studies intended to indicate how variables are related to each other
-comparison of existing groups of children or examination of relations among each child's score on different variables
-primary goal is to determine whether children who differ in one characteristic also differ in predictable ways in other characteristics
-measuring two things that already exist (not changing them)
Advantages of Correlational Design
-only way to compare many groups of interest (boys-girl, rich-poor, etc)
-only way to establish relationship among many variables of interest (IQ and achievement, popularity and happiness, etc)
Disadvantages of Correlational Design
-third-variable (hidden variable) problem
-direction-of-causation problem (what causes what)
Correlation
-the association between two variables
-when variables are strongly correlated, knowing a child's score on either variabel allows accurate prediction of the child's score on the other
Correlation Coefficient
-r
-statistic that indicates the direction and strength of a correlation
-r=0 means no relationship bwt two variables
-correlation ranges from -1 to 1 (strenght or effect size)
-stronger the relationship the closer to -1 or 1
Positive and Negative Correlation
-positive correlation high values of one variable are associated with high values of the other
-negative means high values of one variable is associated with low values of the other
r2
-percent of variance accounted for in one variable by the other variable
-how much one variable contributes to another
-how well can predict one variable if know other
Correlation and Casuation
-correlation does not imply casuation
-reason: direction-of-casuation problem and third-variable problem
Direction-of-Casuation Problem
-the concept that a correlation between two variables does not indicate which, if either, variable is the cause of the other
Third-Variable Problem
the concept that a correlation between two variablees may stem from both being influenced by some third variable (hidden, unexpected)
Why use correlational design?
-many variables, such as age, sex, race, can be studied only within correlational approaches
-these variables cannot be controlled by any researcher
-good when goal is to describe relations among variables, rather than to identify cause-effect relations among them
Experimental Design
-group of approaches that allow inferences about causes and effects to be drawn
-random assignement of children to groups and experimental control of procedures presented to each group
Random Assignment
-a procedure in which each child has an equal chance of being assigned to each group within an experiment
-crucial for being able to infer that it was the varying experience that caused the later differences between the groups
-through random assignment groups should be comparable on all variables
Experimental Control
-the ability of the researcher to determine the specific experiences that children have during the course of an experiment
Experimental Group
-group of children in an experimental design who are presented the experience of interest
Control Group
-group of children in an experimental design who are not presented the experience interest
Advantages of Experimental Design
-allows causal inferences b/c design rules out direction-of-causation and third-variable problems
-naturalistic experiments can demostrate cause-effect connections in natural settings
Disadvantages of Experimental Design
-need for experimental control often leads to artificial experimental situations
-cannot be used to study many differences and variables of interest, such as age, sex, and temperament
Naturalistic Experiments
-a type of experimental design in which data are collected in everyday setting
Two ways to infer causality
-experimental design
-multiple regression
Multiple Regression
-use when can't apply an experimental design
-think of all factors that could affect cognitive development and measure correlation for all other variables (see what contributes and what doesn't)
-statistically removes the effects of other potential predictors
What research designs are used to study development over time?
-cross-sectional
-longitudinal
-microgenetic
Cross-Sectional Design
-research method in which children of different ages are compared on a given behavior or characteristic over a short period of time
-most common and easiest way to study changes and continuities with age
-children of different ages are studied at a single time
-common when central development issue involves age-related changes in typical performances
Advantages of Cross-Sectional Design
-yields useful data about differences among age groups
-quick and easy to administer
Disadvantages of Cross-Sectional Design
-uninformative about stability of individual differences over time
-uninformative about similarities and differences in individual children's patterns of change
Longitudinal Design
-method of study in which the same children are studied twice or more over a substantial period of time
-used when main issues are stability and change in individual children over time
Advantages of Longitudinal Design
-indicates the degree of stability of individual differences over long periods
-reveals individual children's patterns of change over long periods
Disadvantages of Longitudinal Design
-difficult to keep all participants in study
-repeatedly testing children can threaten external validity of study
Microgenetic Design
-method of study in which the same children are studied repeatedly over a short period of time while a change is occuring
-get in-depth depiction of the processes that produce changes
Advantages of Microgenetic Design
-intensive observation of changes while they are occuring can reveal process of change
-reveals individual change patterns over short periods in considerable detail
Disadvantages of Microgenetic Design
-does not provide information about typical patterns of change over long periods
-does not reveal individual change patterns over long periods
Epigenesis
-emergence of new structures and functions in the course of developmetn
Embryology
-scientific study of prenatal development
Lenght of Gestation and three stages of development
-38 weeks
1.zygote/geminal (weeks 1-2)
2.Embryo (weeks 3-8)
3.Fetus (weeks 9-38)
Zygote Stage
-weeks 0-2
-ball of cells
-implantation is most important part of stage
-implantation is 7 to 9 days pc
-placenta by 14 days
Developmental Process
1.cell division
2.cell migration (embryonic period)
3.cell differentiation
4. cell death
Implantation
-zygote embeds itself in the uterine lining and becomes dependent on the mother for sustenance
-before implantation not connected to the mother
-only after implantation can you tell your pregnant
Placenta
-support organ for the fetus
-it keeps the circulatory systems of the fetus and mother seperate but as a semipermeable membrane permits the exchange of some materials between them
Phylogenetic Continuity
idea that b/c of our common evolutionary history. humans share many characteristics, behaviors, and developmental processes with other animals, espcially mammals
Identical Twins
twins that result from the splitting in half of the zygote, resulting in each of the two resulting zygotes having exactly the same set of genes
Fraternal Twins
-twins that result when two effs happen to be released into the fallopian tube at the same time and are fertilized by two different sperm
-only half of their genes are shared
Neural Tube
a groove formed in the top layer of differentiated cells in the embryo that eventually become the brain and spinal cord
Umbilical Cord
tube containing the blood vessels connecting the fetus and placenta
Amniotic Sac
a transparent, fluid-filled membrane that surrounds and protects the fetus
Cephalocaudal Development
the pattern of growth in which areas near the head develop earlier than areas farther from the head
Embryo Stage
-weeks 3-8
-high stage of vulnerability b/c so much is happening (ie miscarriage, vulnerability to drugs)
-rapid development
-axis set early
-cell differentiation
-cell death
What determines which type of cell a stem cell will become?
-which genes are expressed
-location: cell interaction
-hormones
Apoptosis
-genetically programmed cell death
-example is hand with webbing, cells bewteen hands are destined to die
Embryo Stage Milestones
-4 weeks: heart is beating, early body parts visible
-5 to 6 weeks:rapid brain development, facial features, movement begins (meaning development of nervous system, but mom can't feel)
-at end all major organs and parts are present
Fetal Stage
-stage of growth and acquiring functionality
-9 weeks: all internal organs present, responsive to tactile stimulation on face (neural maturation is such that have facial response)
Milestones in Fetal Stage
-16 to 20 weeks: quickening
-28 weeks: point of viability, periods of sleep and waking including REM sleep, responds to external sounds
-last 3 months: triples in size (gains 5 lbs, grows 7 in)
Quickening
-mother feels baby move (baby's big enough)
-depends on mother really and her sensitivity
Viability
-earliest point fetus might be able to survive on own without medical intervention
Fetal Stages: Movement
-starts 5-6 weeks
-full repertoire of movements by 12 weeks
-individual differences in how much fetus moves and these differenc persist
-swallow and breathe in amniotic fluid (no apparent benefit other than practice)
More Active Fetus
-longitudinal study and correlational b/c couldn't randomly assign groups
-more fussy at 6 weeks, more unadaptive to new situations and ppl, more irregular with eating and sleeping habits
Fetal Behavioral Cycles
-rest-activity cycles emerge as early as 10 weeks and become very stable during second half of pregnancy
-longer-term patterns are also apparent with fetus less active in early morning and more active in the late evening
-sleep states in the last 2 weeks before birth are similiar to those 2 weeks after birth
Fetal Experience:Sight and Touch
-visual experience is negligible
-tactile stimulation as a result of fetus' own activity
Fetal Experience: Taste
-recognize flavors of foods present in amniotic fluid
-prefer these flavors right after birth
-do have sweet tooth
Fetal Experience: Smell
-recognize smells present in own amniotic fluid
Fetal Experience: Hearing
-recognize mother's voice from prenatal experience
-can understand to an extent mother's native language (intonation patterns)
-fetus responds to various sounds from at least the 6th month of pregnancy and on
Fetal Learning: Habituation
-habituation is a simple form of learning that involves a decrease in response to repeated or continued stimulation
-32 weeks is earliest observed habituation
-can tell us what fetus knows
Dishabituation/Recovery
-rebound in response due to subsequent change in stimulus
-change in stimulus causes a response again
Heart Rate for neonates or fetuses
-pulse decelerates upon stimulus presentations
-returns to baseline during habituation
-decelerates again to indicate dishabituation
Non-Nutritive Sucking
-sucking is indication of how much like something
-sucking rate decreases during habituation
-increases for dishabituation
Lecanuet et al: fetal learning
-9th month gestation can tell difference between babi and biba
Descaper et al: fetal learning
-long-term retention by 37 week of gestation
-had mothers read same Seuss book aloud
-could discriminate between one rhyming book and another (heart rate deceleration was greater when heard familiar poem than when they heard novel one
DeCsaper and Spence: fetal learning
-non-nutritive sucking
-retained even after birth
-modified sucking to hear story read while in womb indicating they had a preference
Themes: Lessons for Development
-nature/nurture: early development follows genetically determined timeline, but can be affected by experience
-active child:sucking and breathing (practiced muscle movements)
-individual differences:gender; temperament
-continuity/discontinuity:3 stages w/in each stage have cluster of things happening; gradual change but could appear discontinous
Teratogen
-external agent that can cause damage or death during prenatal development
-look at them to gain insight into disorders/problems
-can have direct or indirect influence (sleeper effects)
-time of exposure gives insight into prenatal development timeline
Factors that affect severity of teratogen effect
-dose
-genetic predisposition
-combinations (cumulative impact)
-age/timing (sensitive periods)
Sensitive Period
-period of time during which a developing organism is most sensitive to the effects of external factors
-for most organs sensitive period is before mother realizes she is preganant
Period of Greatest Vulnerability to Teratogens
-embryo period (when growing)
-not susceptible in first two weeks because zygote's not connected to mother
Prescription Drugs
-previously thought placentat was "good" barrier that filters all but know now not true
-sleeper effects (show up later in life, not immediately apparent)
-thalidomide at 4-6 weeks: severe deformity of limbs
-DES: sleeper teratogen; similiar symptoms in adulthood that weren't obvious deformities and happend later in life
Cigarette Smoking
-dose dependent
-mechanism:nicotine constricts blood vessels and increases carbon monoxide, delivering less oxygen to mom and baby (placenta grows abnormally
-baby makes less breathing movements after mom lights up
Effects of Smoking
-retarded growth
-low birth weight
-increases risk of SIDS (passive smoking after birth also increases risk
Alcohol
-dose dependent
-timing of consumption is important
-genetic predispostion is also apparent
-FAS and FAE
Fetal Alcohol Syndrome
-from persistent, heavy drinking throughout pregnancy
-dose dependent but binges may be bad
-facial abnormalities
-slow growth (prenatally and after birth)
-prone to infections
-small head, seizures, mental retardation, deficits in attention, hyperactivity (brain and behavior effects are most noticable)
Fetal Alcohol Effects
-attention problems
-hyperactivity
-no physical effects
Maternal Factors
-nutrition
-disease:rubella (deafness,blindness,deformities, mental retardation)
-stress
Maternal Factors: Nutrition
combination issue, purer case showed LBW, small head size to physical defects, timing important (embryo period)
Maternal Factors: Stress
-shorter gestation
-lower birth weight
-more stress, more physical activity in fetus
-maternal anxiety and depression during gestation associated with behavior problems (ADD, ADHD, CD)
Neonate's Life
-sleeping: 16 hrs (8 hrs in REM and 8 hrs in NREM)
-crying: 2 hrs
-drowsiness: 1 hr
-awake: 5 hrs (active 2.5 hrs, alert 2.5 hrs)
- 2 to 3 hr cycles for all of this in 24 hrs
Sleep
-infants have 50/50 REM and NREM
-declines rapdily by age 3
-adults have 20% REM
-disturbed sleep sigh of problems (neurological problems)
Autostimulation Theory
-brain activity during REM sleep in the fetus and newborn facilitates the early development of the visual system
-eye movement provides visual stimulation
-babies with more visual waking stimulation show less REM
REM
-rapid eye movement
-active sleep characterized by quick, jerky eye movements under closed lids and associated with dreaming in adults
NREM
-quiet or deep sleep characterized by absence of motor activity or eye movements and regular, slow brain waves, breathing, and heart rate
Abnormal Crying
-sign of neurological problems
-double threat because sign of problem and negative response usually by parents (more susceptible to abuse)
Normal Cry
-alertness
-increases around 2 weeks to 6 weeks were peaks and then decreases to about an hour a day
-"evening crying"
Colic
-excessive, inconsolable crying by a young infant for no apparent reason
-usually ends by 3 months
Low Birth Weight
-birth weight of less than 5 and a half pounds (2500 grams)
-average weight is 7 1/2 pounds
Premature
-any child born at 35 weeks or earlier oppose to full term at 38 weeks
Prematurity
-refers to preterm and/or LBW
Small for gestational age (SGA)
-babies that weigh substantially less than is normal for whatever their gestational age
-causes are teratogens (virsuses in the birth canal) or multiple births
-predictive of future problems
Prematurity: Immediate Issues
-small, thin, sleepy, unresponsive
-fussier, hardier to soothe
-at risk for abuse (double disadvantage)
Prematurity: Long-term Consequences
-higher levels of hearing, language, and cognitive impairments
-prone to distractibility, hyperactivity, and learning disabilities in preschool and elementary
-poorer peer and parent relations
-most cognitive and social effects dissipate later in childhood unless severe
Interventions for Prematurity: for babie
-motion, sight, sounds, touch (things they would get in womb)
-massage therapy intervention
Interventions for Prematurity
-show modest effects
-depend on starting point
Nature and Nurture: Genetics
-parent's genotype contributes to child's genotype
-child's genotype contributes to phenotype
-environment influences phenotype and phenotype influences environment
-parent's genotype/phenotype influence environment
environment
every aspect of an individual and his or her surroundings other than genes
Chromosomes
-molecules of DNA that transmit genetic information
-46 chromosomes
-23 pairs of chromosomes (22 autosomal and 1 sex pair)
Human Heredity
-one of each pair from each parent (gametes: sperm and egg)
-every individual has two copies of each gene, one on the chromosome inherited from dad and one on chromosome from mom
Pathway from Genotype to Phenotype
-activation and inactivation of genes (developmental changes)
-dominance patterns: dominant and recessive genes (dominant allele if present is expressed)
Inheritance Patterns: Polygenic inheritance
-inheritanc in which traits are governed by more than one gene
-shyness, aggression, thrill-seeking, and empathy involve polygenic inheritance
gene-environment correlation
-genes and environment are not independent since genetically related parents create the environment
-passive and active
Passive gene-environment correlation
-parents pass on genes and environment, these are correlated so impossible to seperate
-example: mom is talent painist and has paino in home, providing both genes and environment for musical success
Active gene-environment correlation
-child (because of genetic predisposition) changes environment in ways that affect expreession of those very genes
-example: child shows musical promise so parents buy a piano
-"active child": as get older change environment (intial choice is affected by genotype
gene-environment interactions
-affect of gene and environment aren't additive
-reaction depends on predisposition and environment seen in abusive home and conduct disorder example (both factors)
Range of Reaction
-any given genotype has a range of potential phenotypes depending the environment
-example: IQ and lead paint
two premises on which the study of behavior genetics is based
1.to the extent that genetic factors are important, individuals who are genotypically similiar should be phenotypically similiar
2.to the extent that environmental factors are important, individuals who have been reared together should be more similiar than those who have not
Behavioral Genetics
-estimate genetic and environmental contributions to individual differences
-teasing apart effects of genes and environment
Classical Twin Study
-compare correlation for identical twins (mz) and same-sex fraternal (dz)
-mz twins allow cancelation of environment so look at genes specifically
IQ and twin study
-mz twins have higher correlation than dz twins (genetics)
-mz twins reared together are more similiar than those reared apart (environment)
Adoption Study
-examine whether adopted children's scores on a given mearsure are correlated more highly with biological parents and sibilings or adopted parents and sibilings
-ideal comparision is with identical twins reared apart
Heritiability
-statistical estimate of the porportion of variance on a trait among individuals in a given population that is attributable to genetic differences among those indivduals
Heritiability: population concept
-specific to population measured in a particular environment and in a particular time (can't compare groups)
-hertibility applies only to populations, not to individuals
-
Environmental Effects
1. shared (common)
2. nonshared (unique)
Shared Environments
-any environmental facotr that makes people in a family like one another
-intuitive definition is home environment
-low for most traits
Non-Shared Environment
-any environmental factor that makes people in a family less similiar (social, biological, physical
-intuitive definition is things outside home
-high for most traits (esp personality traits)
Neuron
-cells that are specialized for sending and receiving messages between the brain and all parts of the body as well as within the brain itself
-basic unit of the brain's remarkable powerful information system
-across neuron chemical signal within neurons electrical signal
Componets of the neuron
-cell body and nucleus
-dendrites: receive input and conduct it toward cell body
-axon:conducts electrical signal from cell body to next neuron
-synapse:a gap bewteen axon terminals of one neuron and dendrites of another neuron
-axon terminals:release chemicals that touch dendrites to continue the signal
Myelin Sheath
-fatty sheath that forms around certain axons in the body and increases the speed and effciency of information transmission
-helps conduct signal better
Cerebral Cortex
-"gray matter" of brain that plays a primary role in what is thought to be particulary human like functioning
-four lobes: occipital, temporal, parietal, and frontal
Occipital Lobe
-visual processing
Temporal Lobe
-associated with memory, visual recognition, and processing of emotion and auditory sound (hearing and language)
-Left:language, memory, emotional processing, and visual recogniton
-Right:memory, emotional processing, and visual recognition
Parietal Lobe
-spatial processing, cross-modal integration (integrates sensory input with information stored in memory
-primary somatosensory cortex
Frontal Lobe
-planning, inhibition, organizing behavior
-"the executive"
-primary motor cortex
Lateralization
-cerebal hempispheres are crossed wired
-each hemipsher controls opposite side of body
-each hemipshere of brain is specialized for different modes of processing
Left Hemipshere
-language, logical analysis, sequential tasks
Right Hemisphere
-spatial abilities, holistic tasks (ie interperting music: how all combines)
When is lateralization become apparent
-specialization begins early
-most newborns favor right side in head position and reflexive reactions
-greater ERP response in left hemispher for speech and positive emotions, right hemipshere for non-speech sounds and negative emotions
Handedness
-direct effect of lateralization (left hemisphere seems dominant)
-by age 1, most infants show a reaching/grabbing hand preference BUT brain remains plastic for many years
Left Handed People
-less lateralization possibly
-reversal of everything
Neurogensis
-creation of neurons through cell division
-complete by 18 weeks gestation (all the neurons you will ever have are generated)
Migration of Neurons
-through spinal column to final destination
Differentiation and Synaptogenesis
-differentiation: specific type of neuron
-synaptogenesis: form synapses to other neurons (everytime learn something, form synapse)
-complexity of dendrites (spines on branches) increases dendrites capacity to form connections with neurons
-density of synapses indicates level of maturation
Myelination
-cover axons with myelin sheath
-begins in the brain before birth and continues into adolescence or later
Synapse Elimination
-synaptic pruning
-synapses that are rarely activated are eliminated
-axon retreats, dendritic spine pruned away
-continues through adolescence
Why do we have synapse elimination
-6th month old has 2 times as many synapses in visual cortex as an adult (constantly expose to new things and don't know what is important and isn't so take it all in)
Role of Experience and synapse elimination
-synapses not used get pruned (use it or lose it)
Plasticity
-capacity of the brain to be affected by experiencce
-flexibility
-in position of forming and pruning synapses
What is plasticity related to
-lateralization/specialization
-highly specialized cells are less adaptable to change/reorganization (plasticity)
-synaptic pruning
Benefits and Cost of Plasticity
-worst time to suffer brain damage is very early, during prenatal development and the first year after birth (neurogensis and neuron migration)
-"best" time for damage is when synapse generation and pruninh are occuring (plasticity is highest) making rewiring and recovery of function possible
-later when developmental processes are mostly completed and plasticity is low, successful recovery is less likely
-amount of brain damage is good predictor of outcome
Experience-Expectant Processes
-brain expects/needs certain stimulation in order to develop normally
-examples: language, strabismus
-have sensitive periods (when stimulation must occur to develop normally)
Sensitive Periods
-critical periods
-temporary time window for environment to organize brain
-neural organization that does or does not occur during sensitive periods is typically irreversible
Experience-Dependent Processes
-not required for normal development to take place, but nonetheless change the brain
-neural connections are created and reorganized throughout life as a function of an individual's experience
-example:second language, musical instrument
Examples of Experience-Expectant Processes
-visual stimulation for visual development
-language exposure for language development
-oppurtunity to form emotional attachement
Sensation
receiving basic information from the external world through the sensory receptors
Perception
the process of organizing and interpreting sensory information
Preferentail-looking technique
-method for studying visual attention in infants that involves showign infants two patterns or two objects at a time to see if the infants have a preference for one over the other
-prefer patter over solid
-habituation/dishabituation to tell baby can discriminate
Visual Acuity
-the sharpness of visual discrimination
-how clearly they see
-by 8 months of age an infant's vision approaches that of an adult
Testing Visual Acuity
-sinusoidal gratings
-since prefer to look at pattern than homogeneous surface, the narrowest stripes an infant prefers relative to the gray square is assumed to be the smallest pattern he or she can distinguish
-the higher the frequency you can see, the better your discrimination
Why do infants have poor acuity at birth
-acuity is determined by packing of cones of fovea
-cones tell on and off (distinguish one line from another)
-newborns' cones (visual receptors on retina) are less densely packed, not as efficient at capturing light
Contrast Sensitivey
-ability to detect differences in light and dark areas in a visual patter
-infants prefer patterns of high visual contrast
-immaturity of cones is reason for poor contrast sensitivity
Restriction of infants visual experience
-first month or so, don't see richly colorful world (distinguish shades of white)
-visual scanning is restricted to outer edges of object
-hard time tracking objects that move because eye movement is jerky
Object Segregation or segmentation
-identification of seperate objects in a visual array
-cues motion (rod and block studies), physical separation
Rod and Block Studies
-common motion (conveys oneness)
-4 month olds perceive single rod easly
-2 month olds perceive single rod if rod is wider or box narrower
Depth Perception
-cues: optical expansion, binocular disparity and stereopsis, and pictorial/monocular cues
Optical Expansion
-as things move forward they get bigger
-object occludes more of background indicating that the object is approaching
Binocular Disparity
-view from two eyes is different
-object closer to you jumps when switch from one eye to other
Stereopsis
process by which visual cortex combines the differing neural signals cause by binocular disparity resulting in the perception of depth
Pictorial/Monocular Cues
-perceptual cues of depth that can be conceived by one eye alone
-perspective (parallel lines recede indicating objects further away)
-texture (finer detail texture implies object's closer, blurry then away)
-occlusion (object occludes another one so know that the blocking object is closer)
Are the depth cues innate or learned
-optical expansion: 3-4 weeks blink at incoming object (probably not due to experience)
-binocular cues and stereopsis: testing with 3d movies and emerge around 4 weeks; stereopsis has sensitive period (suggest biological maturation,not experience)
-pictorial/monocular: emerge 5-7 months; no sensitive period (most influence by experience)
Reflexes
-innate, fixed patterns of action that occur in response to particular stimulation
Major Motor Milestones
-Lifts head by 4 weeks
-Arms for support 2-4 months
-Reaching/grasping 3-4 months
-Sits without support 5-7 months
-Crawls 5-11 months (7 is average)
-Walks alone 11-14 months
Rooting
-stroke on check
-turn head toward stimulus and open mouth
-f(x): to eat
-disappears after 2-3 weeks
Palmar Grasp/Grasping
-pressure on palm of hand
-firm grasp
-f(x):grab something if lost of support
-disappears 3-4 months
Stepping
-dangle feet above ground
-when feet hit they step
-f(x):walking
-"disappears" around 2 months
Moro/Startle
-loss of support
-arms go out and come back in
-f(x):get grasp if lost of support
-disappears around 6 months
Babinski
-stroke on foot with sharp object
-toes fan out and foot curls in
-f(x):protection if step on sharp object
-changes at 12 months to big toe goes in and out
Importance of Intact Reflexes
-sign of neurological damage if reflex is too weak, too strong, persists too long
reflex disapearance
-shift from involuntary to voluntary control
Motor Milestones
-lift head: 4 weeks
-arms for support: 2-4 months
-reaching/grasping: 3-4 months
-sits w/o support: 5-7 months
-crawls: 5-11 months (7 is ave)
-walks alone: 11-14 months
Traditional View of Motor Development
-maturation (physical and neural maturation)
-based on obervation of orderly progression of motor milestones in Western culture
-about same for all so genetic time table
Problems with Traditional View
-cultural differences (babies held alot vs ones who had stretching and suspension exercise
-stepping reflex
Stepping Reflex
-heavy babies crawl/walk later so if genetic time table why occur later
-water study and added weight study
-weight of legs has to do with stepping reflex (doesn't disappear just legs are too heavy for muscles to support
Dynamic System Theory
-behavior is an integrated system (cognitive, physical, and social abilities)
What are the multiple interacting systems in the dynamic system theory
-brain development
-movement possibilites of body (building new on old)
-motivation (intrisic like personality or extrinsic like goal)
-environment support
The Effects of motor development: self-locomotion and cognitive development
-travel broadens mind
-physical movement around world drives cognitive development
Adolph's View
-learning about world is specific to posture