Reading points - midterm 1 Flashcards
explain the longitudinal study in 1945 on Hawaiian island set up
698 children studies for 40 years
- physician records of mother and baby
- family interactions at home studied
- teachers interviewed
- police, family court and social service records
- IQ and personality tests
- interviewed
explain the longitudinal study in 1945 on Hawaiian island results
showed both biological and environmental factors make up child development
prenatal or birth complications = more likely to develop disabilities
but degree of problems depended on parents income, education, mental health, quality of relationship
by 10 prenatal and birth problems were consistently related to psych difficuties only if child grew up in poor rearing conditions
bio + environ + family problems = serioua leanring and behavioural problems by 10. by 18 police record, mental health difficulties or unmarried parent
but 1/3 = resilient
3 breif reasons why we study child development
raising children
choosing social policies
understanding human nature
evidence on spanking children. alternative?
more often kids were spanked, worse they behaved
sympathy worked better
helping children find positive alternates for their anger
explain the turtle technique
when children feel angry they should remove themself form the situation and withdraw into their shell where they can think until they are ready to emerge from their shell
one study showed positive effects of this were seen 4 to 5 years after completing the curriculum
define meta-analysis
a method for combining the results from independent studies to reach conclusions based on all of them
what did a meta analysis of violent effects of violent video games find
no significant effect led to a law change
how much trust should we place on child testimony study
children play game of simon say
social worker given false script os what happened (but believes it to be true)
when asks children to recount what happened in the game 34% of children eventally changed their stories to corroborate with the social worker… effect of leading questions
explain the romanian adoption study set up
80s and 90s romainan orphanages = awful conditions, nurses actively encouraged not to touch children
malnourished, flat heads from lying on their backs so much, mental retardation, socially immature
adopted by uk parents
compared romainan adoptees to uk adoptees
also compared effect of how long had lived in the orphanage before being adopted
what were the results of the romainian adoption study
weight - if adopted pre 6 months by 6 yo = same weight as british. the later adopted, the less the children weighed
same story with intelligence - impaired visual memory and attention = biggest deficit
20% of post 6 month adoptees showed extremely abnormal behaviour aged 6 years. still persistent aged 15
brain development at 8 yo those who had spent substantial time in the orphanage had unusual low levels of neural activity in the amygdala
what conclusion can we draw from the romainian adoption study
the timing of experiences influence their effects
natursits argue… about human development
evolution has created capabilities we have from an early age
empiricists argue…. about human development
infants posses general learning mechanisms
brief overview of historical foundations of the study of child development
ealry philosophers (plato, aristotle, locke, rousseau)
social reforms movement
darwin
research-based theories
plato’s view of child developemtn
self contorl and discipline = most important goals of education
believed children born with innate knowledge
aristotle view of child development
agreed with plato in terms of discipline but more important to fit to the needs of the child
al knowledge occurs from experience
locke’s view of child development
child = tabula rasa (agreed with aristotle)
goal of child rearing = growth of character
parents need to set good examples
once discipline is instilled, treat as an adult as early as possible
Rosseau’s view of child development
give child max freedom from the beginningchild shouldn’t receive formal schooling until 12 - age of reason
what was the social reform movement born out of
undustrial revolution
how did darwin inspire child development
we should investigate child development as might give us insights into human nature
darwin’s baby biograpy = first methods of studying child development
still underlies ideas today
what are brief the 7 enduring themes in child development
nature vs nurture
the active child - how do children shape their own development
continuity / discontinuity
mechanisms of change - how does change occur
how does sociocultural context influence development
individual differences - how do children become so different from one another
research and children’s welfare - how can research promote childrens welfare
nature vs nuture of schizophrenia
nature - the closer the relation who has schizophrenia, the more likely you are to have schizophrenia yourself up to 50% (identical twin)
nurture - as is only 50% means environment must play a role. also adoptee studies show environmental impact (troubled families made it worse / more likely)
define genome
each persons complete set of herediary information
define epigenetics
the study of subtle changes in gene expression that are mediated by the environment
define methylation
a biochemical process that influences behvaiour by supressing gene activity and expression
explain two study showing increased methylation
amount of stress mothers reported during their childs infancy was related to the amount of methylation in the childs genomes 15 years later
increased methylation in the cord blood DNA of newborns of depressed mothers and adults who were abused as children
what do children attend to and form what age
faces
1 month chose to attend to mother
2 months show emotion to mothers face
when does speech being
9-15 months
what is crib speech and what does it show
toddlers when alone in a room wil often talk to themselves
shows language is internally motivated
difference in play between older and younger children
younger = pretend, learn how to cope with fear and interact with others older = more rule based = self control, turn taking, control own emotions
continuous development theory
the idea that changes with age occur gradually, often in small increments (like a tree growing)
discontinuous development theory
the idea that changes with age include occasional large shifts (caterpillar to butterfly)
define stage theories
approaches proposing that development involves a series of large, discontiuned age related phases
very brief piaget’s theory of child development and how this relates to conservation of liquid problem
children go through 4 stages of cognitive growth
2-5 only attend to one piece of info at a time but by 7 can coordinate more aspects
4-5 yo fail liquid conservation, 7-8 yo pass
define cognitive development
the development of thinking and reasoning
how do we think of cognitive development today
stage theories are useful but outdated
it is a gradual process
supported by fact children show subtely different places of understanding depending which paradigm is used to test a particualr understanding
define effortful attention
voluntary control over ones emotions and thoughts (impulse control, emotional control, attentional contorl for example)
difficulty in effortful attention related with…
poor reading and maths
mental illness
brain areas implicated in effortful attention
limbic area
anterior cingulate
prefrontal cortex
connections in these brain areas develop hugely during childhood. seems to be one mechanism underlying improving efforful attention during childhood
development of these areas reflects environmental influences as well as genetics
define neurotransmitters
chemicals involved in communication between brain cells
- specific genes influence the production of key neurotransmitters
effect of genes and environment on effortful attention in children
infants with a particular form of one gene show differences in effortful attention based on the type of parenting they recieve
among children who do not have that gene, quality of parenting has less of an effect
effects of training programme study in 5 and 6 yo in effortful attention
computerised exercises used to improve the capacity for effortful attention
on examining the anterior cingulate cortex = 6 yo showed increased effortful attention and IQ increased
explain the study examining the role of sleep in promoting learning and generalisation
during first 18 months after birth, sleep appears to promote learning of general, frequently encountered patterns but not specific learning of material only presented once or twice
but
opposite pattern showed at 24 months
what is the active systems consolidation theory
2 interconnected brain areas (hippocampus - details of learnign after experience and cortex - abstraction of general patterns after many experiences) simultaneously encode new information during learning
when are hippocampal memories replayed and why
during sleep which allows opportunities for the cortex to extract general patterns from the specific memories (also works in opposite direction so learning general patterns improves retention of detials for new experineces of the same type
hypothesis why role of sleep changes 18-24 months
18-24 months, hippocampus is too immature to enable the rapid learning of the details of specific experineces - so sleeping doesnt benefit memory for these specifics but the cortex is mature enough to draw out general patterns
evidence to support hypothesis on role of sleep changes 18-24 months
number of exposures to a new word decreases considerably between 18-24 months
pre 18 months dont remeber arbitrary presented sequences of events they have only seen once but after 24 months they do
infants under 18 months who hear several unfamiliar words repeated just before they nap show a type of brain activity during sleep associated with cortical learning processes
children with known impariments to the hippocampus have a much harder time retaining details of their experinces than peers
define sociocultural context
the physical, social, cultural, economic and historical circumstances that make up any child’s environment
what does brofenbrenner’s bioecological model take into account for childs development
people children interact with
physical environment they live in
institutions that govern their life
general characteristics of society
descrbie cross cultural differences in where babies sleep
USA - parents bedroom at first, 2-6 months move to oen bedroom
Japan, Italy, South Korea - same bed as mum for first few years and older children also in the same room. father can be in different room
define socioeconomic status
a measre of social class based on income and education
low SES in USA…
children do worse
health problems in infancy more likely
brain average less surface area
more emotional problems
smaller vocab and decreased IQ, math and reading
more likely to have a baby out of marriage and drop out of school
define cumulative risk
the accumulation of disadvantages over years of development
3 characteristics of resilience
positive personal qualities
close relationship with at least one parent
close relationship with at least one other adult
Scarr’s 4 factors that make children even from the same family different
genetic - even identical twins = diff gene mutations
different treatment by parents and others
different reactions to similar experineces = 69% of negative events triggered diff reactions in siblings
different choices of environment - the active child
what is the active child
as children grow older they increasingly chose activities and friends for themselves = influence their own development
what were the results of interventional program that taught children they could improve their own intelligence
when told they were improved significantly more than their peers who were not teachers cited cihldren 3 times more who had this intervention as showing significant change in attiude and motivation in class than those who had not undergone this intervention
what are struggle stories
stories of real people who overcome problems and still do great things
telling kids these works
explain the steps of the scientific method
question
hypothesis
develop a method to test the hypothesis
use the resulting data to draw a conclusion regarding the hypothesis
reliabliity
the degree to which independent measures of a given behaviour are consistent
interrater reliabliity
the amount of agreement in the observstions of different raters who witness the same behaviour
test-retest reliability
the degree of similarity of a participants performance on two or more occasions
internal validity
can the effects of the experiment be attributed to variations that the researchers intentionally manipulated
external validity
how widely can the findings be generalized to different children in different places at different times
validity
the degree to which a test measures what it is intedned to measure
how does clinical interviews work
questions can be adjusted in accordance with the answers the interviewee provides
troubled family observation set up and results
naturalistic settings
troubled = at least one child labelled as out of control
income and age controlled fo
parents of children in troubled homes = more self-absorbed and less responsive to their children
viscious circle emerged
1 child acts hostiel or agressive
2 parents get angry
3 child escaltes level of hostility
4 parents escalate agression even further
positive and negative about naturalistic observation
can determine causeation
some beahviours only occur occasionally
what is structured observation
a method that involves presenting an identical situation to each participant and recording their behaviour
results of structured intervention study:
child asked to comply to mothers instructions to do less fun task then tidy up
child who complied wholeheartedly when first asked tended to avoid playing with the forbidden toys for longer, also more likey to comply and put toys away
retested near 4th bday - showed same type of compliance they had as a toddler = stable
positives and negatives of structured observation
all children in same situation so direct comparisons can be made
no extensive info about childs subjective experince
not naturalistic or open ended
what are variables
attriubutes that vary across individuals and situations
what are correlational designs
studies intended to indicate how two variables are related to each other
eg can estimate how long children spend reading based on their reading scores
direction-of-causation problem
the concept that a correlation between two variables does not indicate which, if either variables is the cause of another
third-variable problem
the concept that a correlation between two variables may stem from them both being influenced by some third variable
why do we use correlations when they can be so problematic
many varibales cannot be studied experimentally
sometimes we just want to know about relationships, not causes
define experimetnal designs
a group of approaches that allow inferences about causes and effects to be drawn
define random assignment
participants have an equal chance of being assigned to each group within an experiment
define experimental control
the ability of researchers to determine the specific experinences of participants during the course of the experiment
define experimental group
the group of participants in an experimental design who are presented the experince of interest
define control group
the group of participants in an experimental design who are not presented the experience of interest but in all other ways are treated similarly
what is a cross-sectional design
a research method in which participants of different ages are compared in a given behaviour of characteristic over a short period of time
what was found out about background TV and childs play
it disrupts it
what is a longitudinal desgin
a method of study in which the same participants are studies twice or more over a substantial length of time
practical and validity questions
what is a micorgenetic design
a method of study in which the same participants are studies repeatedly over a short period of time
in depth depiction of what causes change
study development as it occurs
counting-on strategy study
microgenetic design
4 and 5 yo did not yet use the counting on strategy but knew how to add by counting from one
11 week period = lots more problems presented than normal
discovered harder problems didn’t start this change, it periodically started to appear even on easy problems
generalisation tends to be slow
when would we use microgenetic designs and why
typically used when a basic pattern of age related change has already been established and the goal becomes to understand how change occurs
ethical issues in child developemtn research
research cannot harm children
informed consent comes from the parent
preserve anonymity
discuss any results with parents which might be important to the child’s welfare
try counteract any foreseen negative consequences
correct any inaccurate impressions the child may develop from the study
aristotle - view on prenatal life
is fetus all ready made just tiny
or does it develop in sucession
define epigenetics
the emergence of new structures and fucntions in te course of development - what aristotle thought
how did aristotle study develop
opening chick eggs
what do the Beng people of west africa believe about when life starts
every life is a reincanation of another
only when the stub drops off the umbilical cord does the new life begin
what are gametes
reproductive cells - egg and sperm that contain only half the genetic material of the other cells in the body
what is mitosis
all division that produces gametes with 1/2 genetic info
when are female eggs produced
during her prenatal development and that is all she gets
define conception
the union of an egg from the mother and sperm from the father
define zygote
a fertilised egg cell
define embryo
name given to the developing organism from 3rd to 8th week of prenatal development
define fetus
name from 9th week to birth
define mitosis
cell division that results in two identical daughter cells
sex differences in survivial and health
used to be thought there was a bis towards male
showed not true is equal
female fetuses less likely to survive early gestation, resulting in slight male bias at birth
but male fragility
explain male fragility
males more likely to low birth weight fetla distress during labour learning disabilities higher infant mortality less likely to survive
what is cell migration
the movement of newly formed cells away from their point of origin
what is cell differentiation
after several divisions we start to get cell specialization`
define embryonic stem cells
no fixed function and can develop into any body cell
so how do we know what cell to turn into what , when and where
what is apoptosis
genetically programmed death
role of hormones in sex differentiation
if androgens are present then male testes develop
around the 8th week after conception the fetus can begin creating this hormone and if it does then boy
go through early development of zygote to fetus
journey through fallopian tube, doubles number of cells approx twice a day
4th day = hollow sphere with a bulge of cells called inner cell (identical twins most liekly to develop now)
end of first week implantation in uterine lining and dependent on mother (only about 1/2 of zygotes conceived make this)
how identical twins occur
splitting in half of the zygote resulting in 2 zygotes
how fraternal twins occur
two eggs happen to be released into the fallopian tube at the same time and are fertilised by 2 different sperm
so only half genes in common
define amniotic sac
a transparent fluid filled membrane that surrounds and protects the fetus
define placenta
support organ for the baby
keeps circulatory systems of the mother and fetus separate but a semipermeable membrane permits the exchange of some materials between the two
define umbilical cord
a tube containing the blood vessels connecting the fetus and placenta
define neural tube
a groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord
after implantation of the zygote…
cell differentiation
inner cell mass = embryo
3 layers each with different density (top - nervous systme, middle - bones, muscles, cirulatory system, inner layers of skin + internal organs, bottom - digestive system, lungs, urinary tract, glands)
u shaped groove forms down centre of top layer
folds at top move together and fuse - neural tube
one end of this tube will swell and develop into the brain, the rest is the spinal cord
define habituation
a simple form of learning that involves a decrease in response to repeated or continued stimulation
define dishabituation
the introduction of a new stimulus rekindles interest following habituation to a repeated stimulus
fetal learning through habituation
fetuses as young as 30 weeks gestation show habituation to both visual and auditory stimuli indicating the CNS is sufficiently developed at this point for short term memory and learnign to occur
heart rate increases to mothers own voice
preference for own amniotic fluid after birth
define phylogenetic continuity and why is useful
the idea that because of our common evolutionary history, humans share many characterstics, behaviours and developmental processes with other animals especially mamals
eg studying fetal alcohol syndrome in rats
what lasting effect does the things that happen in the womb leave ont he fetus
preferences of taste
dr seus story - preffered the version they were read in the womb
should we school our kids in the womb
no
amniotic sac means fetus can hear sounds and pitch, not individual words and no meaning understanding
most common hazard to fetuses
miscarriage - spontaneous abortion
most tend to occure before mum even knows she is pregnant
majority of fetuses that miscaryy very early have severe defects that make development impossible
define teratogens
an external agent that causes damage or death during prenatal development
what is the crucial thing in teratogens effect
their timing relative to development
many can only cause damage if are present during sensitive period of development
what was minamata disease
mercury poisoning of fetus by mother eating contaminated fish from a particular lake
define sensitive period
the period of time during which a developing organism is most sensitive to the effects of external factors; prenatally the sensitive period is when the fetus is maximally sensitive to the harmful effects of teratogens
thalidomide
50s and 60s
serious birthd efect occured only if mother took drug during 4th and 6th week after conception
was fine if took before or after
dose response relation
a relation in which the effect of exposure to an element increases with the extent of exposure
what makes some teratogens like smoking difficult to study
happen in combination eg smoking = low ses so more pollution anyway
define fetal prgramming
programme the physiological set points that will govern physiology in adulthood
so prenatal malnourished mother - increased risk of obese child as nutritional deficiency in the womb never resets itself
this was found in dutch hunger study (was useful as ses for example wasnt an issue)
explain the sleeper effects of teratogens example
DES used during pregnancy in 40s and 50s to prevent miscarriage
in adolesence and adulthood their offspring had elevated rates of cervical and testicular cancer
antidepressents and pregnancy
treating depression during pregnancy can help reduce risj of postpartum depression
we are unsure about the risks of antidepressants on babies
evidence is inclusive
CBT type approach will probably be best
opiods as teratogens
highly damaging - fetus can become addicted
neonatal abstinence syndrom - form of drug withdrawal seen when fetus exposed to opiods in the womb are born
-low birth weight, problems with breathing, feeding and seizures
illegal drugs as teratogens
as they are designed to mimic neurotransmitters = havoc with developing brain
cigarettes as teratogens
less O2 to fetus
fetus breathes less whilst mother is smoking
fetus will metabloize some of the cancer causing agents
slowed fetal growth, low birth weight, increased infant death syndrome, decreased IQ, hearing deficits, cancer
dose-response relationship
timing - effects are greatest early in gestation
alcohol as teratogens
leading cause of fetal brain damage
mothers tend to be +35, college educated and employed
alcohol crosses placenta and goes into fetal bloodstream
fetus has less ability to metabolize and remove alcohol so remains in fetuses system longer
FAS - facial deformities, mental retardation, attention problems, hyperactivity
SIDS
sudden infant death syndrome
infant under 1 year, doesn’t seem to be a cause
cultural influences - african and native americans most liekly, hispanic and asian least likely
inadequate reflux response? as reflexes are in process of changing
to prevent but baby to sleep on back (but do need to provide supervised tummy time)
environmental pollutants as teratogens
PCB exposure (lake michigan fish) - newborns with small heads, newborns who had undergone highest exposure had slightly lower IQ scores as long as 11 years later china - pollution related birth defects flint river water policy change - corrosion of water pipes so lead poisoning, neurotoxin, ADHD. disproportionatley effected low SES
maternal factors on fetal health
girsl under 15, baby more likely to die before first bday
older mothers - fetal chromosomal abnormalities, birth complications, autism
old father has also been implicated, ADHD increased risk
nutrition of mother
all babies nutrients come from mum
too little folic acid = high risk neural tube deficits
general malnutrition = slow growth of fetal brain. but hard to study as often SES at play but was studied during dutch hunger winter
diseases in mum that can effect baby
- rubella
if contracted early in pregnancy then major malformations, deafness, blindness, intellectual disability
diseases in mum that can effect baby
- STIs
cytomegalovirs (herpes) - most common cause of congenetial infedction in birth canal - blindness or even death
HIV - can pass to fetus, breastmilk can transmit but could also protect?
diseases in mum that can effect baby
- influenza
schizophrenia x3 more likley if flu during first trimester. infection may act on genes that make individuals more vulnerable to mental illness
diseases in mum that can effect baby
- maternal illness
may lead to autism in children who are generally susceptible potentially die to high levels of cytotines in the developing brain or due to an autoimmune response
diseases in mum that can effect baby
- zika virus
microcephaly - small baby head
issues in brain development
sexual transmission
diseases in mum that can effect baby
- women’s emotional state
difficult to test
higher levels of mother stress = more active fetuses - probably linked to stress hormones mum released
continues after birth - higher levels of behavioural problems in child at age 4
so maybe prenatal yoga and meditation is a solution
crying
evolution - we react to baby crying
mother responds more than father? mum has more of the solutions (eg breastmilk) but mum and dad equally good at distinguishing their own babies crying from others
crying increases after birth peaking at 6-8 weeks then decreases by 3-4months
parental understanding of crying important to avoid abuse and general distress in parents
sugar can help lower pain
in mums arms can help
how does swaddling works
provudes a high level of tactile stimulation and warmth
practiced in many cultures
how should we respond when baby cries?
prompt response precited less cries months later
vs
infants where cries were ignored during the first 9 weeks cried less during the next 9 weeks
colic
excessive or inconsolable crying by a young infant for no apparent reason
-allergy
-immature gut development
ends around 3 months leaving no ill effects
whats considered -normal birth rate -low birth rate -very low birth rate premature small for gestational age
7.5 pounds
5.5 pounds
3.3 pounds
at 37 weeks or earlier
weigh substantially less than is normal for whatever their gestational age
as a group LBW…
increased medical complications, neurosensory deficits, illness
decreased education achievement, IQ
but closely tied in with low SES
why might there be increased low birth rates in china
pollution so impaired O2 transport across the placenta
hypothesised pathway for why low birth weight babies have psychiatric and dev problems
white matter reduction, ventricular enlargement, and so abnormal brain development occurs
explain intervention program for LBW babies
parents now allowed to touch and interact
kangeroo care - allowing skin to skin contact
parents as incubators
promote breastfeeding
decreases mortality, increases growth and attatchment = quickler out of hospital
to compensate for little touch, LBW babies recieve progamme of moving their arms and legs as when more active = more alert = gain weight
parents singing to infant
tend to be fussier, harder to get to sleep, harder to get a schedule going. in telling parents this it helps alot
delayed dev milestones, closer to gestational age than birth age
social support system for parents very important
3 important notes on intervention programmes
gains are moderate and diminish over time
sucess on an intervention depends on the initial health status of the infant
cumulative risk factors at play
Rutter’s multiple-risk models
higher incidence in english children gwoing up in families with 4 or more risk factors
define genotype
the genetic material an individual inherits
define phenotype
the observeable experssion of the genotype including both characteristics and behaviour
define environment
every aspect of an individual and their surrpundings other than genes
what are the five realtions that are fundamental in the development of every child
parent’s genetic contribution to childs genotype
contribution of childs genotype to their phenotype
contribution of childs environment to their phenotype
influence of each childs phenotype to their environment
infuence of childs environment on genotype
define chromosomes
molecules of DNA that transmit genetic information
chromosome are made up of DNA
define DNA
molecules that carry all the biochemical instructions involved in the formation and functioning of an organism
define genes
selections of chromosomes that are the basic unit of heredity in all living things
what is the human genome made up of
only 2% genes
what we used to think of as junk DNA plays a supporting role in influencing genetic transmission by regulating the activity of protein-coding genes
explain human heredity
46 chromosomes 23 pairs in the nucleaus of each cell sex = the exception, otherwise both are same general x shape one chromosome from each parent
sex determination
sex chormosome
female - 2x
male - 1x 1 y (little one)
sperm contain both x and y so it is the sperm that decide the sex
a gene on the y chromosome encodes a protein that triggers the prenatal formation of testes
subsequently testes produce testosterone
define mutation
a change in a section of DNA
random spontaneous error, others are caused by the environment
most are harmful
most occur in germ cells and can be passed to offspring
occasionally makes offspring more viable = DARWIN
define crossing-over
the process by which sections of DNA switch from one chromosome to the other; crossing over promotes variability among individuals
explain dominant-recessive patterns and name diseases which transmit via this
occurs only when an individual has two recessive alleles for the condition
PKU
sickle-cell anemia (remeber malaria benefit)
cycstic fibrosis
tay-sachs
name 3 genetic disorders resulting from a dominant allele
huntington disease
neurofibromatosis
FOXP2 - gene running in an english family producing speech, language and motor difficulties
define heterozygous
carry one normal of the gene and one defected
so in the case of sickle cell would be protected against malaria but not poorly
what is polygenetic inheritance
interaction among multiple inherited genes in conjunction with the environment eg cancer heart disease diabetes 1 and 32 asthma psychiatric disorders - autism, ADHD
define GWAS
genome wide association studies
suggest each gene has just a small effect on its own
explain sex linked inheritance with examples
some single gene conditions are carried on x chromosome and muhc more common in males as no second x to contain the dominant
male pattern baldness
hemeophilia
red-green colour blindness
ducheene muscular atrophy
fragile x syndrome - most common form of heritable intellectual disability
explain chromosomal abnormalities
zygote with wrong number of chromosomes tend not to survive
down syndrome - mothers egg does not divide properly = extra chromome 21 (mum over 35 much more likely)
kinefelter syndrome - extra x chromosome in men (small testes, elongated limbs, infertility)
turner syndrome - missing x chromosome in women (XO) - short, stunted sexual development at puberty, inferitlity
name two diseases resulting from gene abnormalities
williams syndrome - small section of 25 genes on chromosome 7. less deletion = less impariment
7q11.23 duplication syndrome = duplication of same genes that are missing in williams - weak speech and language but strong visuo-spatial skills
explain regulator gene defects
regulator genes control the expression of other genes
eg male born with female genetalia
explain 3 diseases of development that have some genetic base that we just dont understand yet
dyslexia - highly heritable
tourettes - complex pattern
autism - 500-1000 candidate genes associated, de novo mutations = non-inhertied mutations are associated
define endophenotypes
intermediate phenotypes including the brain and nervous system that do not involve overt behaviour
are all genes on at once
NO
define regulator genes
genes that control the activity of other genes
genes never function in isolation
development = the continuous turning on and off of genes
what proportion of genes have alleles
1/3
define dominant allele
the allele that is present gets expressed
define recessive allele
the allele that is not expressed if a dominant allele is present
define hetero and homo zygous
heter - two different alleles for a trait
homo - having two of the same alleles for a trait
define polygenetic inheritance
inheritance in which traits are governed by more than one gene
define norm of reaction
all the phenotypes that can theoretically result from a given genotype in relation to all the environments in which it can survivie and develop
eg - can be studies by placing non-human with same genotype in different environments
explain PKU
disorder resulting from a defective recessive gene on chromosome 12
prevents metabolism of amino acid - phenylalamine
if phenylalamine allowed to build up in the bloodstream = impaired brain development, severe intellectual development
but tend to be identified shortly after birth and placed on a strict diet
explain the link between child abuse and genotype
the effects of the abuse function with childs gentoype = combination of environment and genetic factors
x-linked gene MAOA
when is genetic testing done
at any point in life
define pharmocogeneti testing
use info about individuals genetic makeup to determine which course of treatment is more liekly to be effective
define carrier genetic testing
genetic testing used to determine whether prospective parents are carriers of specific disorders
typically offerent to eastern european jewish parents - tay-sachs
also to african americans as sickle cell
to solve would use IVF
define prenatal testing
genetic testing used to asses the fetuses risk for genetic disorders
offered to all in usa
encouraged in those with risj factors
analyze maternal blood to screen (false negatives though)
dignositc tests = fetal cells (amniocentisis = amniotic fluid 15-20 weeks, CVS = placenta 10-13 weeks)
define aneuplodity
missing or extra chromosome
trisomy 21 - down syndrome
trisomy 18 - edwards syndrome
trisomy 13 - patau syndrome
define newborn screening
tests used to screen newborn infants for a range of genetic and non-genetic disorders
all newborns in usa = heel prick test screening for 30-50 diff disease biomarkers
define active child
the child is a source of their own developemtn
active creators of their own environment
nature evokes behaviours in others
select own environment once self-locomotion begins
explain methylation in identical twins and what this tells us
3yo = very similar
50 yo = very different
how the environment changes our genes
how does poor maternal care affect methylation
affects methylation of genes involved in glucocticoid receptors = then this influences how animals deal with stress themselves
define behaviour genetics
the science concerned with how variation in behaviour and development results from the cobination of genetic and environmental factors
define heritable
refers to any characteristics or traits that are influenced by heredity
define mulitfactorial
refers to traits that are affected by both environmental as well as genetic factors
what are the two premises that underlie how we separate the effects of environment and genes
individuals who are geneticlaly similar should be phenotypically similar
ie behaviour should run in families
individuals who are reared together should be more similar than those who are reared apart
monozygotic vs fraternal twins
mono = identical frat = 50% gene similarity
what do adoption studies show us
are given measures / traits more highly correlated with sibling or adopted family
explain family studies of IQ
identical twins resemble each other more than fraternal
as they get older the degree in variation acocunted for by their genetic similarity increases
so genetic influences on intelligence increases with age
people actively control their own environments as they get older so IQ matches genetic better
define heritability
a statistical estimate of the proportion of the measured variance on a trait among individuals in a given population that is attributable to genetic differences among those individuals
in the us heritability seems to vary as a function of …
SES
high heritability does not impl…
immutability
so we can still try to cure it
GCTA-genome wide complex trait analysis found
childrens educational attainment and social advantage appear to share some of the same genetic roots
same genes are involved in intelligence across age
heritability rarely exceeds…
50% so environemtn must be at play
define neurons
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
define sensory neurons
transmit information from sensory receptors that detect stimuli
motor neurons…
transmit info from the brain to muscles and glands
interneurons ….
intermediate between sensory and motor neurons
what do glial cells do
cells in the brain that provide a variety of critical supportive functions
outnumber neurons 10 to 1
formation of myelin sheath
help with brain health - protect brain and aid in regeneration
define cerebral cortex
the gray metter of the brain that plays a primary role in what is thought to be particularly human like functioning from seeing and hearing to feeling emotion
define lobes
major areas of the cortex associated with general categories of behaviour
the four lobes are responsbile for... occipital temporal parietal frontal
occipital - visual
temporal - memory, visual recognition, processing emotion and auditory info
parietal - spatial integration, sesnsory input integrating with memory
frontal - organizing behaviour
define associated areas
parts of the brain that lie between the major sensory and motor areas and that process and integrate inputs from these areas
define cerebral hemispheres
the two halbes of the cortex; for the most part, sensory input from one side of the body goes to the opposite hemisphere of the brain
define corpus callosum
a dense tract of nerve fibres that enable the two hemispheres of the brain to communicate
define cerebral laterization
the specialization of the hemispheres of the brain for different models of processing
define neurogenesis
the proliferation of neurons through cell division
begins 42 days after conception
virtually complete by midway point of gestation
we do continue to generate new neurons thoughtout life
can be inhibited by stress
how do new neurons get to the right place
helped by radial glial cells that provide scaffolding
define arborization
enormous increase in size and capacity of the dendritic tree
define spines
formation on the dendrites of neurons that increase the dendrites capacity to form connections with other neurons
define mylenation
the formation of myelin (white matter) AROUND THE AXONS OF NEURONS THAT SPREADS AND INCREASES INFORMation processing abilities
-begins deep in the brain and moves out towards the cortex
occurs rapidly after birth
slows somewhat during toddlerhood
continues into young adulthood
what are ERPs
event related potentials
change in the brains electrical activity that occur in response to the presentation of a particular stimulus
eg ERps in response to native speech shows their language growth over the next few years
MEG
detects magnetic fields generated by electrical currents in the brain
noninvasive way to study fetal brain
during the last trimester fetuses are encoding info about repetitions of sounds
fMRI in child developemtn
child needs to be over 6 years old to stay still enough
but can be used on sleeping infants as young as 2 days
DTI - diffusion tensor imaging
rs-fMRI = resting state fMRI - can be used to study how brain networks develop
PET
positron emission topography - detects brain metabolic processes
but involves injecting radioactive material into the brain
primarily used for diagnosis
NIRS
near infra-red spectroscopy
detects metabolic changes that lead to differential absorption of infrared light in brain tissue
head does not have to be totally still
can be used on kids who have had cochlear implants (where fMRI cannot)
explain the white matter differences between us and chimps as we develop
initial = same but then chimps show a mature pattern of mylenation at the point of sexual maturity earlier than observed in humans
synaptogenesis
the process by which neurons form synapses with other neurons resulting in billions of connections
note timing and rate of synapse production vary in different cortical areas
complete much earlier in visual compared to frontal
timing is likely to contribute to the onset of various abilities
explain synapse elimination
overabundance of neurons and synapses from synaptogenesis
what is synesthesia and when can humans experinece it
blending of different types of sensory input
in infancy before connections between sensry areas are yet to be pruned
define synaptic pruning
the normal development process through which synapses that are rarely activated are diminated
- occurs at different times in different brain areas
- adolesence = major brain developemtn and pruning
- amount of gray metter = huge decrease 11-12 years old
