Class Notes (1,100,000)
CA (630,000)
UTSC (30,000)
Psychology (8,000)
PSYB32H3 (600)

PSYB32H3 Lecture Notes - Dishabituation, Twin, Habituation

Course Code
Mark Schmuckler

of 6
Psyb20-lec 3
-Canalization : sometimes attributes are predetermined and you need envrionmental factors to
push them outta that
Range of reaction principle
-Gottesman, each person’s unique genetic structure, it determined the response to the
environment that people have.
-the genotype will actually set the limits on the range of possible phenotype that an individual
will portray
-portray phenotype in respect to different environments
-ex: child a b and c child a has great genetic perspective of intelligence, b medium and c doesn’t
have. Does this mean that child a will end up with a higher iq? No
It sets the range under which the child can express intelligence in regards to the environment
Look at the childs intelligence in genetics in respect to environments
You see in child a in the restricted environment they don’t do as well same with b and c
-first idea: the range of child a is the limits, it is really big, so having good genetic potential,
gives the child a large range to fall into
-compared to the child c has limited genetic potential has more of a restricted range.
-larger genetic potential, larger the range
-having predetermined genetics does not only influence you to fall into a certain location
-issues with range: how do u actually go about and measure this?
-to truly determine the range, we need to take people and put them in a wide range of
environments but we don’t have that level of control
-issue 2: we need individuals with identical genetic structures and put them in these different
environments which is difficult to do
-difficult to truly investigate
-kinship study: members of the same biological fam are compared to see how similar they are
in attributes
-look at identical twins and see how similar they are in a particular attribute and compare the
similarity to fraternal twins (who share 50% of genetics)
-if attribute is hereditary, monozygotic more similar than dizogotic
-just because 2 individuals live in the same home doesn’t mean they share the same
environment each person experiences environments differently
Scar and mccartney model
-we assume that genes and enviro are independent
-there are correlations between genes and enviro and there are models to show
-if parents have irritable genes, then they alter the childs environment and pass those irritable
genes on to the child causing both the genes and environment to have a factor on the child
phenotype, making it more likely that the child is irritable
-childs phenotype has direct influence on the childs environment the feedback loop
-although the childs genotype stays fixed for life, the environment will eventually change
causing change in the gene environment interaction
-their model produces 3 types of gene environment correlations
-passive gene influences: parents contribute to dev in 2 ways
1. provide genetic material
2. structure environment socially and emotionally
Because environments provided created by parents depend on their genotype environment will
be generally matched to children’s genotype
-evocative gene influences: child attributes will aaffect the behavior of other people. Influence
how other will react with that child ex: a happy baby will smile at people and people will give
that baby more attention and positive interaction.
-the reason the child is evoking these reactions is partly based on the childs genetic
-active influence (niche picking): they are gonna seek out social, have a lot of friends, go on play
dates niche picking: the child picks their own niche for themselves
Environmental influences on gene expression
-genes and environment, the relationship is not a one way slate
-the influences are bidirectional they affect behavior and experiences which effect gene
-epigemtic framework: dev results from bidirectional influence from genetics and environment
Questions about genotype-environmental interactions
-strong tendency to think about the way genes operate with a dev program
-its like a computer program, but one thing we should know is that the models that we’re
discussing are far to complex for any standard notion of set of instructions that proceed along a
certain path
-characteristics depend on the outcome of various attractions . it self modifies, so this analogy
doesn’t hold
-genes in some sense are surpreme: genes determine phenotype
-once the genotype is determined the phenotype is fixed, but this is not true especially
considering the range of reaction that allows u to fall into diff places depending on your
-ex: if u are not in an environment that provides with alcohol, then you can not become an
alcoholic, even if it is in your genes
-genotype sets the absolute limits on the nature of the phenotype: not true
-its only the capacity in respect to a certain environment
-genes determine tendencies: we are still making assumptions about the nature of the
-we are saying that an individual with the tendencies to be excited is going to be excited in
every environment
-It is possible but we are not taking into account different environments
Perceptual development
Perception is the process by which we gain knowledge about the environment
Localization techniques
-present the infant with an object see how they respond
-oriented response: put something in their visual field and expect them to look at it, there is
some form of localization
-visual localization: present visual target and look to see if the baby fixates to the target
If you put it to the side, see if infant turns his head towards it
-auditory localization: present auditory target and see if the child turns toward the sound, or
look where the sound source is coming from
-what are infants actuall perceiving , can they discriminate
Habituation dishabituation technique
-we present the infant with a stimulus and repeatedly present it to the infant until they get
bored and stop responding to the stimulus (habituation stimulus)
-when they stop responding they are habituated
-once they are bored we take another set of stimuli and measure the infants renewed interest
-if the infant can discriminate in stimulus, they will show more interest in the new stimulus
-they have dishabituated and can discriminate between the 2 objects presented
-our ability to know about what infants are seeing, or only as good as the experiments we are
-we are inferring the infants ability, because we can never truly know what the infant is seein
-fixed trials: present the infant with a preset number of exposures of the habituation stimulus
-problems: say the kid really loves red stars and doesn’t ever want the presentation to end, or
some infants just don’t like them they have different interests then we test em with the
dishabituation stimulus, the 2 infants are at different levels of interest so its difficult to
interpret the nature of the dishabituation stimulus because they are at diff levels of interest
-infant control: keep presenting stimulus until the infants interest has declined, then we can say
the infant has habituated
-with this the infants have diff amounts of exposure, but this way they will be at the same level
of interest
-its geared toward infants interest
-infant attention:
1. cardiac deceleration: we look at the infants heartbeat and look at the mean number of
heartbeats and when we present new stimulus look to see the change in the heartbeat.
When infant is interested their heart rate slowsdown, increase is due to fear
-It is often used with auditory
2. visual fixation: wanna know if they are interested, look to see if they are looking, when they
are not interested they look away
-look to see an increase in visual fixation when interested
3.non nutritive sucking: take a pacifier infants will modulate sucking rate in reference to