Midterm 1 Flashcards
(240 cards)
1
Q
what are sciences?
A
- systems of formal theories
- they construct their theories by testing opposing casual hypotheses (models)
2
Q
what are hypotheses called
A
models: stated in mathematical or logarithmic form
predict unknown facts through logical (or mathematical) derivation from a model.
3
Q
what are some universals of childhood?
A
- childhood fear of strangers
- classification of age
- sweets preferred
- thumb sucking
- turn taking
4
Q
what is one purpose of developmental theories?
A
explaining the universals of childhood
5
Q
what is a theory?
A
explains known facts and predicts unknown facts by identifying cause-effect relations that hold for the known and the unknown
ceteris paribus (all-other-things being-equal)
6
Q
example of scientific theory
A
Darwin’s theory explains the known fact of species- differences as an effect of evolution by natural selection vs. Lamarckism which is the inheritance of acquired characteristics
Does experiment with rat tail length:
Predicts that any newly discovered population that is subject to selection rules differing from its ancestors will evolve different characteristics over time that can eventually lead to speciation - Lamarckism predicts that predicts that short tailed rats will predominate in one group if you cut off the tails of all the rats and interbreed them all
Lamarck’s hypothesis failed
Darwin’s worked
7
Q
what is a model?
A
Models are provisional theories that posit mutually exclusive cause-effect relations
Cause-effect relations are established by testing competing models
8
Q
How do we test a hypothesis?
A
1) choose the appropriate measurement
2) gather data using some method
3) use data yielded to draw a conclusion
9
Q
What is measurement?
A
measure must be directly related to hypothesis!
measure must be reliable
- interrater reliability
- test-retest reliability
measure must be valid
- internal validity: are effects due to manipulated conditions? (e.g. advertising)
- external validity: does the test generalize? (preference for one sip isn’t the whole can)
10
Q
what are characteristics of good measures?
A
1) reliable
2) valid
11
Q
what does it mean to be reliable?
A
the degree to which independent measurements of a behavior under study are consistent
12
Q
what is interrater reliability?
A
do observers agree?
indicates how much agreement there is in the observations of different rates who witness the same behavior
If we measure preference by facial expressions, observers probably won’t agree as much as if we measure preference by self- report.
13
Q
what is test-retest reliability?
A
are measures consistent over time?
measures of a child’s performance on the same test, administered under the same conditions, are similar on two or more occasions
14
Q
what does it mean to be valid?
A
refers to the degree to which is measures what it is intended to measure
reflect only what is manipulated, generalize outside the measurement setting
15
Q
what is internal validity?
A
Are effects due to conditions manipulated?
refers to whether effects observed within experiments can be attributed with confidence to the factor that the researcher is testing
E.g. preference may come from product advertising or from product taste - A blind taste-test would be a better measure b/c it would eliminate brand loyalty as a variable and thus have higher internal validity than a bottle- to-bottle comparison
16
Q
what is external validity?
A
does this test generalize?
refers to the ability to generalize research findings beyond the particulars of the research in question
you want to draw more general conclusions
to test its external validity, you’ll have to study participants from different backgrounds with different research methods
E.g. preferences for one sip might not generalize to preferences for a whole can
17
Q
what are the two problems with correlation?
A
Hypothesis: Tobacco smoke contains substances that are toxic to human tissue when deposited by contact
1) ambiguous direction of causation (maybe the direction of causation is reversed. maybe people who have cancer are nervous which causes them to smoke)
2) potential third variable (correlation doesn’t mean causation)
18
Q
what are characteristics of experimental design?
A
- random assignment
- experimental control
nonsmokers –> smokers –> high disease
vs
nonsmokers –> nonsmokers –> low disease
ONLY experimental designs will allow you to draw a conclusion about causation
19
Q
examples of non-experimental designs?
A
1) no control, no pretest
2) no control, pre-post test
3) control, no random assignment
20
Q
what are some problems for studying developmental causes
A
- problems of measurement:
1) old people misunderstand instructions
2) young children perseverating answers (repeating them over and over)
3) infants don’t pay attention - problems with age being confounded with non-age related factors (if a kid get’s better at cards over a span of 18 months you have to realize he’s also getting older)
21
Q
what are three designs for examining development? (identifying age-related changes)
A
1) cross-sectional designs
2) longitudinal designs
3) microgenetic designs
22
Q
what is a cross-sectional design?
A
you collect data from a population/subset at ONE specific point in time - used to describe characteristics that exist in a population, but not to determine cause-and-effect relationships between different variables - utilizes different groups of people who differ in the variable of interest (share other things like race, socioeconomic) - variable is not manipulated
you take measurements in 2000 of how racist the 5, 20, 40, and 80 year old populations are
You see that there is a change with age and that 80 y.o. had more racial sterotypes than 5 y.o.
Even if that were the case you couldn’t say that it was because they were older- it could be because they are from different generations and grew up in different cultures
(bar graph)
23
Q
what is a longitudinal study?
A
follow the same people from when they’re 5 to when they’re 80 (1925-2000): if you find the same thing, does this mean it’s showing the same results? well you should probably follow other 5 y.o. that were born 15 years later in a different generation and see if their results were also the same
(linear graph)
24
Q
what is the microgenetic design?
A
- Choose children slightly younger than when a change normally takes place
- Provide experiences that are hypothesized to set the change in motion
- Observe the change while it is occurring
The strategy is to experimentally induce a developmental change - you make a change happen by manipulating causal variable - observe before, during, and after the change takes place - you see the change happening
Multiple tests in a short period of time, increased density of trials - can have multiple subjects like the math problem solving strategies experiment
25
what is the "positive effects of experience"?
the idea is that in the period E you have lots and lots of “special experiences” and what you should find is that the control group and experimental group should diverge - there should be immediate and delayed effects - what happens is that eventually they converge because there’s catch up growth - these special experiences are something that children will just encounter later
26
what are "negative effects of experience"?
hypothetical patterns of development resulting from the effects of "impoverishing" experience - experimental on isolation
27
why not make everything innate?
if everything was already hardwired then it’d be hard to adapt/learn - there’d be no plasticity and everything would be robotic - if the environment changes the only way for adaptation to occur would be at individual differences by chance
28
examples of innate abilities? not innate?
- Newborn colts can run moments after birth
- Newborn rats prefer sweet tasting foods to bitter ones
vs.
- speaking english
-driving a car
29
what are the two theoretical limits on innateness?
1) Environmental change requires fast adaptation: supposed it was hardwired that when you see a bannana you go for it - the bannana used to be brown but now it’s yellow so you need to adapt
2) Genes are limited in number: true but it’s a theoretical limit - even with an limited number of genes you can get unlimited types of behaviors
30
what is plasticity?
the capacity of brain to change in response to experience or damage
31
what are three kinds of evidence that support plasticity?
1) Effects of general experiences that almost all normal infants have regardless of history, culture, child-rearing practices, etc. (experience-expectant plasticity)
2) Effects of specific, idiosyncratic experiences the child will have as a result of his or her own life circumstances (experience-dependent plasticity)
3) Recovery from brain damage
32
what is experience-expectant plasticity?
refers to the role of general human experience in shaping brain development - the normal wiring of the brain partly results from general experiences (everyone has them):
- patterned visual stimulation
- voices and other sounds
- movement
- manipulation
When an expected experience is absent, the areas of the brain that would have normally become specialized as a result of that experience can be reorganized to serve some other function (deaf people have better peripheral stimuli)
These sources activate or stabilize some synapses and cause other synapses to be eliminated
33
experimental evidence of experience-expectant plasticity?
Experiments on cats and other mammals have shown that if a brain is chemically ‘silenced’ during fetal development, the mammal ends up with significant abnormalities --> it's almost as if one sense took over to compensate for the missing one
By shutting off auditory stimuli, Mriganka Sur rewired the brains of ferrets so that signals from their eyes fed into their auditory cortex
Ferrrets could even move toward objects detectable by sight alone
its as if the cells of the auditory cortex were trained to be from the occipital cortex
34
written english vs. ASL experiment
evidence of experience-expectant plasticity
- normally the left hemisphere is used for language processing b/c of the brains expectations of spoken language
- when a language depends on perception of spatial location and motion (like ASL) areas within the right hemisphere are also part of the language systems of the brain --> when you shut down part of the brain it can be taken over by another part of the brain
Studies of visual processing in congenitally deaf individuals suggest that certain aspects of visual development are enhanced after auditory deprivation. These include the perception of and attention to peripheral visual space and to motion
35
what is experience-dependent plasticity?
proof of plasticity - brain is also wired by idiosyncratic experiences - experience can help select and preserve the synapses that the body produces
stimulus poor vs. stimulus rich environment - when the rats were in the rich environment they were interacting with each other more and they moved/saw more = better exercise --> more dendritic spines on cortical neurons, more synapses per neuron, thicker cortex, more supportive tissues (such as blood vessels and glial cells)
36
what are examples of experience dependent plasticity?
1) Violinists with years of practice have increased cortical representation of the fingers of the left hand
2) Skilled Braille readers also have enlarged cortical representation of the hand they use to read Braille text
more synapses don’t make you necessarily smarter - you have to have the right synapses at the right place at the right time
37
what is recovery from brain damage?
proof of plasticity - recovery from brain damage shows that plasticity differs with age
- Very early damage (during neurogenesis and neuron migration) results in profound deficits like for pregnant women during Heroshima
- Later damage (during synapse generation and elimination) is ‘best’ because plasticity is highest
- better for kids to have brain damage than adults because immature parts of the brain can take over the parts that were lost
- some problems/deficits only show up at later ages though
38
what are some limits of plasticity?
subcortical structures seem much less plastic (lower level structures seem to be less plastic)
- hippocampus
- amygdala
- hypothalamus
39
what does the hippocampus do?
consolidates memories and supports mental maps
40
what does the amygdala do?
colors experience with emotions
41
what does the hypothalamus do?
the source of the sex drive and other appetites
42
what is the old development claim?
William James
babies have to learn to see the world, no experience in the womb
without perceptual experience, infants are born into a “blooming buzzing confusion”: he means that children would literally think the world was constantly blooming
43
what used to be the dominant view on development?
perceptual development required sensory input
44
what is psychological atomism?
the doctrine that the mind constructs its awareness by of reality by mixing sensations (like brightness and solidity) through "mental chemistry" (associations)
they had an idea that our most basic experiences (like a table) are not actually the basics - they’re composed of something still more basic - the most basic form of experience was these atoms called sensations called primary ideas
45
who invented psychological atomism?
john locke, bishop berkley, wilhelm wundt, hermann helmholtz
46
what was the atomists' thought experiment?
Suppose a man born blind, and taught by his touch to distinguish between a cube and a sphere... Suppose the cube and sphere placed on a table and the blind man to be made to see: ...[could he] by his sight, before he touched them... distinguish and tell which is the globe, which the cube?
Molyneux and Locke agreed that he wouldn’t be able to tell - but you can make an argument for either case - you couldn’t find out the difference between experiences in one modality vs. the other because this experience is impossible - the only other option was to consider it in infants but you never know what a baby thinks
47
what is the "proof" of psychological atomism?
the argument for ambiguity
the image on retina does not provide information about size, distance, or even shape (Berkley)
decreasing an objects distance causes an increase in retinal image size
different sized objects with the same visual angle have the same retinal size (a small object that's close looks to be the same size as a big object that's far away)
when an object is getting closer to you all your retina sees is that the object is growing in size (blooming)
48
what is the view of modern cognitive scientists on development?
do not assume that“in the womb” =“no experience
49
fetal experience and sensory structures?
Sensory structures (i.e., receptors and nerves) for experiencing the world are present (in some form) during fetal development
50
touch in the womb
- the fetus's body parts come in contact with one another
| - an 18 week old fetus sucks its thumb, grasps its umbilical cord, rubs its face
51
taste in the womb
- the fetus can detect the flavors of the amniotic sac
- preferences for sweets is already present
they directly injected blue die into the amniotic fluid which was either sweet or unflavored (sacarine) as the baby drinks the blue die and excretes it into the mom’s pee - she will either excrete alot of blue or a little - those with sugar dye peed a bright blue which indicates they prefer it - we have an innate preference for sweets
52
smell in the womb
- the fetus seems to detect the smells of the amniotic fluid, which are influenced by what the mother eats.
- newborns turn more to cotton pads soaked in their own amniotic fluid than to control pads
amniotic fluid has sort of a fecal smell - each women’s is slightly difference based on what mom eats - the result is that each fetus environment has its own unique smell - how do we know that the fetus knows what that scent is? they put two pads next to a newborn, one with its mothers amniotic fluid and another with a different women’s- they must have been able to smell it previously and thus had a preference for it
53
hearing in the womb
some sounds can reach the fetus better than others such as: mom's heart beat, breathing, swallowing, voice (it's actually noisy on the inside and quite on the outside = crying)
during the last trimester the baby hears:
- external noises elicit changes in movement and heart rate
- when the mother starts speaking the fetus’ heart rate briefly decelerates (indicating detection of novelty)
low frequency tones like dad’s voice isn’t heard well but in the last trimester the baby can hear all of these because they elicit changes in movement and heart rate of the fetus
54
hearing in the womb in the third trimester
In the 9th month, fetuses can learn to recognize some of what they hear
measured babies heart rate based on phonetic switch: you see if babies can detect if the phoneme has switched - shows they’re able to hear
when you’re presented with a stimulus again and again and again - either you have sensory adaptation (you’re no longer able to sense something) or you have habituation: when a person effectively ignores a stimulus that is changing a little bit until they are no longer aware of it (you forget you’re wearing socks) and when you wiggle your toes and feel your socks again that’s dishabituation (regain awareness)
55
habituation in the womb
hearing in the womb
Lecanuet et al. (1987):
36- 40 weeks GA,
DV: heart rate
IV: phonetic switch (babi/ biba vs babi/babi; vv)
Results: 79%of19fetuses recovered in babi/biba; 71% of 14 fetuses in biba/babi
DeCasper & Spence (1986)
Fetuses were read“Cat in the Hat”vs“The King, the Mice, & the Cheese”; tested after birth
IV: story,familiarityofstory
DV: preferential sucking
Moms would read to their unborn babies - they were tested after birth to see which of the two stories they wanted to hear by taking a recording of the new story vs. the old story and whenever the baby would suck on the pacifier it would read a story - initially they preferred the new one to the old one - but after a couple of days they wanted the familiar instead of the new - it shows they can differenciate (began with novelty and moves to a familiarity preference)
56
sight in the womb
the fetus may react to a bright light shown against the mother’s tightly stretched abdominal skin, but its visual experience is very slight
in priniciple, they baby has the ability to detect brightness differences but other than that there’s no visual stimulus in the womb
57
does in the womb = no experience?
only for sight!
touch, smell, taste, and hearing are all developed in the womb and they're born with preferences
58
what is a mature visual system?
1. Adult normal acuity is 20/20
2. Adults find edges and internal features
3. Adults see distinct objects
4. Adults perceive depth
59
visual acuity at birth?
at birth, visual acuity is about 20/400; by 8 months, infants’ vision is comparable to adults
the change occurs due to the maturation of the size, shape, and arrangement of the cones in the fovea (which are highly sensitive to resolution)
60
what is visual acuity?
maturation is the key to visual acuity
Schematic representations of cone size, shape, and spacing in adults (a) and infants (b). Difference results in infants only catching 2% of light on fovea (vs. 65% in adults)
although visual acuity doesnt normally improve with experince, visual acuity can decline with experience - althought visual acuity is highly heritable, reading increases the risk for needing glasses
61
visual scanning
infants are attracted to moving stimuli but their eye movements aren't smooth
jerky movements because of immature fovea since cones aren’t developed and there’s just a few big ones and in an adult the size, shape, and arrangement is bigger
As the fovea matures (by 2 - 3 months), infants can track moving objects smoothly if the objects are moving slowly.
Infants’ visual scanning ability is limited to focusing on perimeters or corners.
62
what is a contour?
in visual scanning, babies are biased towards perimeters and contours
contours: there’s a contrast in brightness - we have cells in our visual cortex that respond to contrast which is sufficient to detect contrast (innate the baby already has it)
63
how does a baby look at a face vs. an adult?
baby: looks at places of high contrast to find out more about the shape
(bottom-up knowledge)
adult: looks at the hairline to tell gender
looks at mouth to tell their attitude/emotions
scans areas that have high value about social interactions (top-down knowledge)
64
what is pattern perception?
Pattern perception requires visual acuity, visual scanning, and the ability to analyze and integrate the separate elements of a visual display.
Kanisza Square: is it four circles with a square in the middle or 4 separate pac man figures?
65
babies and the kanisza square
8 month old babies stare longer at the kanisza square, like they think it's weird, which shows that they not only can see the Kanizsa square but can interpret it as a real object which can act as an occluder
5 month olds cannot do this (the 5 month stares longer at the image where the first part is two pac men and then second is the kanisza square)
66
perceiving objects
Our retinal images of people and objects change as they move behind occluders, move away from us, or toward us
can they tell an object retains its characteristics despite the retinal image? (a person doesn’t look like they’re floating just because you can’t see their legs)
okay great we have patterns and contrast but it doesn’t matter if we can’t perceive objects as a whole
67
what are the three characteristics that involve perceiving objects?
1) segregation ambiguity
2) shape ambiguity
3) size/distance ambiguity
68
movement and ambiguous segregation
image 1: a rod with a block in front of it
image 2: two smaller rods with a gap between them
image 3: a full rod
if the baby understands more than just the retinal image they should see the second rod instead of the third and understand that even though the block was in front of it, it was just covering up the rod, not that the rod was actually in two pieces
69
object segregation and knowledge
As infants get older (8 mo), general knowledge aids in ambiguous object segregation
the ability to segregate has it’s limits when the objects get more complex
the image of a tube with a box in front of it...the baby probably can't tell that those are two separate things and will rotate them together
70
shape ambiguity
tilted trapezoid or rectangle?
you reach for things that are closer so they tested the babies to see if they reached for things that are nearer - put a tilted rectangle near a baby and see if they think it’s a trapezoid and vice versa
based off of if the babies reach for an object - they'll reach for things that are closer so based off that you can determine if a baby is seeing a rectangle or trapezoid
71
which experiment tested for size/distance ambiguity?
Slater, Maddock, and Brown Experiment (1990)
perceptual constancy!
one block was small and closer to the baby while the other was bigger and farther away
72
what did the slater, haddock, and brown experiment discover?
perceptual constancy!
shape and size constancy in new borns = innate ability
73
how do babies have perceptual constancy?
depth cues!
74
conclusion on William Jame's hypothesis?
- babies do not perceive objects that change distance to change shape
- babies do not perceive objects that change distance to change size
- humans do not require sensory experience to avoid a “blooming, buzzing confusion” --> the only possible way for this to be true is for newborns to perceive depth
75
what experiment was used to determine depth perception in babies?
the visual cliff
early studies suggest that babies didn't perceive depth until they began to crawl
when testing mountain goats, they put them on a table and the baby goats would freeze - they said it must be because they realized there’s a depth difference between the ground and the table - then they said they could do the same thing with babies but with a table
76
is the visual cliff effect in determining depth perception?
no - crawling experience probably isn't necessary for depth perception
new born rates never cross over to the deep side. when placed on the deep side of the visual cliff, pre-crawling 3-month olds show decelerated heart rate whereas crawling 12-month olds show increased heart rate - tells us about whether babies can see heights and if they fear them
77
What is Berkley's funny idea of the visual system?
there’s only one eye in this image - but there’s an angle of dissperity between two eyes - the difference of what’s happening between your left and right eye gives you information about depth
78
what are the depth cues used by infants?
1) convergence
| 2) optical expansion
79
what is convergence?
turning inward of the eyes so they point to the same point in space
when your eyes hurt when you bring something closer to you - this happens in babies
80
what is optical expansion?
visual image increases as it comes closer and it occludes more of the background
trying to cover Dr. Opfer’s head with my thumb - if i move my thumb closer it covers more of his head
the fact that newborns can use optical expansion to cue depth is evidence against the blooming buzzing theory because they don’t see everything coming at them all the time - it tells them the object is coming closer and not increasing in size
81
which experiment demonstrated conversion and optical expansion cues in newborns?
In Slater’s studies both conversion and optical expansion cues were present, allowing depth to be registered and thus allowing size and shape constancy
82
what is binocular disparity?
depth cue used by infants
The two eyes do not send the same signals to the brain because there are different retinal images of the object in each eye.
Closer objects generate greater binocular disparity
(the picture of the two football players)
83
binocular disparity in relation to distance?
if you have three images all at the same distance then they’ll yield the same optical disparity
at different distances, the closer the object the
greater the retinal disperity - what this means is that if there were a cell in the brain that could code retinal disparity then you could register depth directly without the need for learning - these cells were recently found! that’s how you know depth innately
84
what is stereopsis?
the process by which the visual cortex combines the different neural signals from each eye to create depth perception
using both your eyes to perceive depth
85
what are binocular disparity cells?
what they find is that the response of this cell is perfectly proportion to the degree of disperity from the two eyes - it codes retinal disperity and makes stereopsis possible
when stereopsis is achieved it means that the binocular disparity cells are mature
86
when does stereopsis begin?
it begins suddenly around 4 months and is completed within a couple of weeks (newborns registered depth but just not through stereopsis)
Achievement of this process signals the maturation of the binocular disparity cells in the visual cortex
87
what are monocular cues? examples?
perceptual cues of depth that can be perceived by one eye alone
1) relative size
2) object interposition
88
what is relative size
Objects that are larger appear to be closer to us than smaller objects
89
what is object interposition?
Near objects partially occlude objects that are farther away
the larger object looks closer - other clues that tell you the larger one is closer is the brightness and the occlusion of the image in the background by the image in the foreground
90
what is adult vision like?
1. normal acuity is 20/20
2. find edges and internal features
3. see distinct objects
4. perceive depth
91
what is adult hearing like?
1. localize the source of the sound
| 2. detect rhythm and melody in music
92
what is adult perception?
- combination of hearing and vision
| - they combine information from different modalities
93
which experiment disproves the "blooming BUZZING confusion"?
when there’s a sound the baby doesn’t know where it’s coming from - this is false due to the clicker experiment - the baby doesn’t just hear clicking coming from everywhere, it localizes it
94
when does an infant achieve adult auditory perception?
5-8 years
95
what is auditory localization?
newborns can turn toward the direction of sound
96
infant music perception?
4-mo: prefer consonance to dissonance
4.5 mo: prefer Mozart w/o pauses
5 mo: detect melody
mary had a little lamb via flute or obo - if you bore them with flute and then play it with the obo they stay bored
97
what is consonance vs. dissonance?
consonance: sounds good
dissonance: two notes sound really bad together
harmonics: wave frequencies are different so they don’t blend together
98
what is intermodal perception?
Infants are able to combine information from two or more senses.
Very young infants link oral and visual experiences --> as they get older, infants integrate visual and tactile explorations
Infants at about 4 months can integrate speaking sounds with a picture of lips moving.
99
when can infants integrate speaking sounds with pictures of moving lips?
4 months
| intermodal perception!
100
what is the McGurk effect?
when seeing the lips and hearing you hear ba, va, tha, da - then when you turn off the sound you can clearly tell the lips are making different sounds - when you close your eyes you just hear va - this shuws that visual articulatory information is integrated into our perception of speech automatically and unconsciously - the sllable that we perceive depends on the strength of the auditory and visual information and whether some comporimse can be achieved. regardless intefration of the discrepant audiovisual speech sullables is effortless and mandatory - shows that development of speech perception
101
what is perceptual development?
development of many perceptual systems occurs very early and simultaneously with input making it difficult to tell whether experience is necesary - many aspects of vision however develop later birth but without the need for expereinece
102
what is the table that tells you approximately when your baby should physically be able to do X
motor milestone table
103
when should a baby be able to lay prone and lift its head?
0-1 months
104
when should a baby be able to lay prone with its chest up and use its arms for support?
2-4 months
105
when should a baby be able to roll over?
2-5 months
106
when should a baby be able to support some weight with its legs?
3-6 months
107
when should a baby be able to sit without support?
5-8 months
108
when should a baby be able to stand with support?
5-10 months
109
when should a baby be able to pull itself up to stand?
6-10 months
110
when should a baby be able to walk using furniture for support?
7-13 months
111
when should a baby be able to stand alone easily?
10-14 months
112
when should a baby be able to walk alone easily?
11-14 months
113
what are the events of a motor milestone table in order?
1) prone, lifts head
2) prone, chest up, uses arms to lift up
3) rolls over
3) supports some weight with legs
4) sits without support
5) stands with support
6) pulls self up to stand
7) walks using furniture for support
8) stands alone easily
9) walks alone easily
114
what was the old view on motor development?
Early pioneers Arnold Gesell and Myrtle McGraw believed that motor skills were determined mainly by neurological maturation of the nervous system/brain (and not due to any kind of motor activity) - not really held by anyone today
115
what was the evidence that supported the old view on motor development?
there was huge cultural variation in early motor activity, yet tiny cultural variation in onset of walking
e.g. swaddling vs. African exercises to "strengthen" joints
116
what is the modern view on motor development?
the dynamic systems perspective
117
what is the dynamic systems perspective?
the view that different aspects of maturation affect each other to form a dynamic system
1) maturational effects on development
2) environmental effects on development
3) practice effects on development
118
what are maturational effects on development?
- Limited by development of perception
- Limited by development of the body growth
you put a baby on it’s stomach and it learns to roll over so it can see more
119
what are environmental effects on development?
- Limited by nutrition
| - Limited by motivation
120
what are practice effects on development?
- New skills are built out of prior abilities
(need to reach a prerequisite)
- Motor pathways are refined through use
121
what are two trends for the growth of the body?
1) Cephalocaudal Principle of Development
| 2) Proximodistal Principle of Development
122
what is the cephalocaudal principle of development?
The upper portion of the body develops quicker than the lower part of the body
head to tail trend of development
e.g. an embryos head is huge compared to its feet
123
what is the proximodistal principle of development?
The middle part of the body develops quicker than the outer part of the body.
interior of body developes faster than extremities
e.g. organs develop before the fingers
124
what are the general trends of the development of motor control?
1) self-regulated vs. reflexive movement
2) differentiation of individual movements
3) integration of individual movements
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what is self-regulated vs. reflexive movements?
disappearance of reflexes
movement from reflexive to self-regulated movement
126
what is differentiation of individual movements
grasping and reaching
a lot of early movements aren’t defined - over development, these movements become differentiated - movements that were just blobs and eventually get separated over time
127
what is integration of individual movements?
locomotion
movements that are different and the child learns to put them together over time
128
what are reflexes?
Reflexes are tightly organized inborn behaviors that occur in response to particular stimulation
e.g. head turn: brush cheek->infant turns head: adaptive because it allows the infant to locate nipple
129
why do we have reflexes?
innate reflexes are a product of our evolutionary history - they're only adaptive in *non-human* primate babies
e.g. Babinski relfex
130
what is the Babinski reflex?
curls toes and then releases when brushed - helpful for monkeys because they can grab things with their feet
131
what are innate reflexes that are adaptive in all primate babies
- grasping
- Moro reflex
- rooting
- sucking
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what is the moro reflex?
a baby's hands fling outwards when the baby is dropped - arms can help catch her fall
133
what are some innate reflexes that are present in adults, babies, and non-human primates?
1) diving reflex
2) breathing reflex
3) blinking reflex
134
what is the diving reflex?
they hold their breath, their heart rate fluctuated to accomodate for the depth of the water based on the pressure that they feel, also the babies open their eyes
135
what are higher cortical areas?
higher cortical areas: you have more layers of control - initially you just have spinal control, then limbic system, and then the cortical layer of control - so if breathing is entirely reflexive then you wouldn’t be able to talk because you need to control your breath in order to talk
136
what happens to innate reflexes that are present in babies?
Some simply disappear as they come under control of higher cortical areas (e.g. sucking, grasping, Babinski)
137
how do we know that the innate reflexes that disappear are disappearing because they have come under control of higher cortical areas?
The reason we know these reflexes are in higher cortical areas is because these reflexes also reappear in dementia, which involves cortical degeneration - old people with dementia redevelop grasping, the Babinski reflex, etc
138
what is the stepping reflex? when does it disappear?
- Movement entails lifting one leg then the other as in walking
- Elicited by holding a newborn under the arms so that his or her feet touch a surface
- Reflex disappears around 2 months but not because higher cortical connections are made!
139
what experiment showed that the stepping reflex doesn't disappear?
Zelazo, Zelazo, & Kolb (1972):
had infants practice stepping --> resulted in prolonging the reflex
then when 7 m.o. are put on a treadmill they step (the reflex is back!)
kicking continues throughout infancy (which is just like stepping but horizontal)
140
what was the Thelen experiment?
stepping reflex experiment (1995)
Noted that chubbier babies generally begin walking later than slimmer babies (1995)
Possibly, the rate at which the legs get chubby (in all babies) is greater than the rate at which legs get strong (in all babies)
- Put baby fat-sized weights on legs of stepping babies (eliminated reflex)
- Put non-stepping babies in a tank of water (got the reflex back)
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differentiation in reaching time span?
1) pre-reaching
2) voluntary reaching
3) reaching for moving objects
4) arms work independently
5) reaching for moving objects that change direction
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when do babies exhibit pre-reaching?
newborn - 7 weeks
143
when do babies exhibit voluntary reaching?
3 months
144
when do babies exhibit reaching for moving objects?
5 months
145
when do babies exhibit their arms working independently?
7 months
146
when do babies exhibit reaching for moving objects that are changing direction?
9 months
147
what are false reaches?
Part 1: the ball is rolling towards her and she reaches her hand out in anticipation that the ball is coming
Part 2: even though the ball isn’t coming anymore, she still reaches for the ball because she sees it start rolling- she can control trajectory for object and time it but she needs something that tells her that if the green barrier is present, you need to stop reaching - it’s like she has 2 of the three switches
148
do infants learn to reach by looking at their hands and objects?
when searching for objects in the dark:
- Infants between 4 and 8 months reach readily and accurately in the dark for sounding objects and luminous objects (this means that they don’t have to see their arm in order to reach for the object)
- Longitudinal study of 7 infants tested weekly revealed onset of reaching in light no different from reaching in dark (the first time a baby sees it in the dark they can find it in the light and vice versa - this means it’s not based on a baby’s modality)
visual information is used to adjust grasp after about 9 months
149
what are the differentiations in grasping?
1) ulnar grasp
2) transfer object from hand to hand
3) pincer grasp
4) manipulate objects with improved coordination
5) manipulate objects with good coordination
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when do babies perform the ulnar grasp?
newborns
151
when do babies transfer object from hand to hand?
4-5 months
152
when do babies perform the pincer grasp?
1 year
153
when do babies manipulate objects with improved coordination?
13-18 months
154
when do babies manipulate objects with good coordination?
19-24 months
155
what shows the development of locomotion in a baby?
motor milestone table
156
what was the experiment that was done on integration in locomotion?
Adolph, 1997
microgenetic study!
strategies for moving down an incline:
- crawling
- backing
- prone
- sitting
- walking
when difficulty of incline is increased, everything goes haywire and the babies drop a developmental level - if development is due to maturation then this wouldn’t happen because it’s not like you reset the nervous system when you increased the incline - something else must be happening
microgenetic study - practice does let babies go from one locomotion to the other and helps them get used to new things they didn’t use before and reject some that they had previously used - what this means is the baby will learn its safe to do new things
157
what causes children to move from one ability in locomotion to another?
Variation and selection
- Practice helps children select among alternatives already in the repertoire
- Regressions are common
Adolph's microgenetic experiment: allowed kids to get used to new things and reject things they'd previously used
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where do children get their genes?
children get all their genes from their parents
genotype parent - genotype child
each parent contributes 50%
159
what is a gene?
a segment of DNA that is the code for the production of one particular protein
160
how do genes affect development?
- by specifying a protein template
| - by regulating other genes
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what are identical genes called?
homozygous
162
what are non-identical genes called?
heterozygous
163
what are the two types of genes?
homozygous and heterozygous
genes come in pairs
chromosomes also come in pairs
164
what are gene pairs called?
alleles
The difference between homozygous and heterozygous gene pairs (alleles) has implications for how the child’s genotype affects his/her phenotype
165
what are the hereditary and environmental interactions?
parent's genotype - children's genotype
child's genotype - child's phenotype
child's environment - child's phenotype
child's phenotype - child's environment
166
what are two ways that children's genes affect their behavior?
genotype child - phenotype child
1) One gene can control behavior (Mendelian inheritance)
2) Many genes can control behavior (Polygenic inheritance)
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what is it called when one gene can control behavior?
Mendelian inheritance - traits are controlled by a single allele
recessive and dominant alleles
BB vs. Bb
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what is it called when many genes control behavior?
polygenic inheritance
169
what is an allele?
different forms of genes
curly vs. straight
170
what was the Scott & Fuller experiment?
1965
found that all bansenjis were afraid of a novel person, whereas the cocker spaniels were seldom afraid.
some psychological traits are controlled by a single gene. was this one?
1) they crossbred pure cockers and basejis - all fearful (FF, Ff)
2) crossbred the hybrids (Ff) - one was fearful
3) crosbred hybrids with purebred cockers - 1/2 fearful
* this shows there's one single fear-controlling gene that's dominant*
171
what is PKU?
it has a mendelian distribution
people with PKU disorder have a gene that makes them ineffective at breaking down phenylalanine - total language loss and mental retardation (prevented by monitoring the child’s diet)
172
what is SLI?
mendelian distribution
Specific Language Impairment has been linked to the FOXp2 gene
they have a problem with inflectional morphology
if you say something is a “fep” and show them two, they won’t be able to say that they are “feps”
173
what are some examples of polygenetic distribution?
traits and behaviors of psychological interest that involve contributions by several genes:
```
infant temperament
shyness
aggression
risk-taking behavior
empathy
TV viewing
```
174
what kind of graph is used to show a polygenic distribution of a trait/characteristic?
histogram
| shows a normal distribution (bell curve)
175
what is population genetics?
attempts to find a role for genes by looking at differences between people and linking it to (genetic) family history
ask how much variation in the behavior of a group is a function of genetic differences (”heritability”, h^2) versus environmental differences
176
what are the different levels of heritability?
how much variation in the behavior of a group is a function of genetic differences ?
h^2 = 1: all of the differences stem from genetic differences
h^2 = 0: none of the differences stem from genetic differences
h^2 = .5: half of the differences stem from genetic differences
177
what is an experiment to establish heritability?
take all the bare fruit flies ones with the super bristly ones - if you find that it differs from the parents then it implies that heritability is greater than zero - if it’s the same then it’s zero
178
what was Tyron's Study of Maze Running?
1942
This chart depicts the progress Tryon made in selectively breeding rats for their ability to get through mazes after only a few errors.
The critical step Tryon made was to cross-foster the rats (bright rats raised by dull rats, dull rats raised by bright ones). Regardless,offspring scores resembled those of their parents.
179
what is a way to determine environmental influence in humans?
Compare identical twins raised apart (some environmental similarity) to identical twins raised together (more environmental similarity) to estimate environmentality— the proportion of variance due to environmental variation
180
what is a way to determine heritability in humans?
Compare identical twins raised together (some environmental similarity) to fraternal twins raised together (same amount of environmental similarity?) to estimate heritability—the proportion of variance due to genetic variation
181
what are the three laws of behavior genetics?
1) all human behavioral traits are heritable (h^2 > 0)
2) The effect of being raised in the same family is smaller than the effect of genes (h^2 > e^2)
3) A substantial portion of the variation in complex behavioral traits is not accounted for by the effects of genes or families (if you add h^2 and e^2 they are less than 1)
182
if not all of behavior traits are determined by heritability or environment, what is it due to?
if not due to genes or the environment then a lot of genes are a result of chance or interactions between the two variables or effects of experiences that are not shared by siblings (sex/birth order)
183
what is the norm of reaction?
environment of child - phenotype of child
the range of all possible phenotypes in relation to all possible environments
Genotypes are expressed differently in different environments
h^2 depends on environment
Even when there is a substantial genetic contribution to a psychological trait, the amount of variation in the trait that is explained by genetic similarity (i.e., heritability) depends on the subjects’ environment
184
what is an example of the norm of reaction?
assume that depression/ happiness is entirely the result of genetics ....who is most likely to be depressed?
1) Mr. A's identical twin has a history of depression
2) Mr. C's fraternal twin has a history of depression
3) Mr. D's fraternal twin has no history of depression
4) Mr. B's identical twin has no history of depression
what this means is in one kind of environment h^2 is 1 but in another environment it’s 0
or when someone has the serotonin gene vs. # of stressful life experiences increases chances of suicide
185
what was the turkenheimer norm of reaction experiment?
2003
calculated IQ heritability for twins who differed in socioeconomic status
if very poor, heritability is close to zero - if rich heritability is close to one
186
norm of reaction in relation to PKU
In an environment with NO phenylalanine, the defective gene won’t make any difference in behavior
In an environment WITH phenylalanine, the gene will make a huge difference in behavior
187
how are children active sources of their own development in two ways?
child phenotype - child's environment
1) They actively evoke certain responses from others (e.g., calm, beautiful babies)
2) They actively select surroundings and experiences conducive to their interests, talents, and personality characteristics (they find their own niche, but they may differ at how good they are at it)
h2 +e2 ≠1
188
what is the development of the nervous system?
blastocyst to brain
189
what is a blastocyst?
it’s a clump of cells, from when the zygote is dividing in the brain
190
what are the six basic processes from blastocyst to brain?
1) gastrulation
2) neurulation
3) neurogenesis
4) neural specialization
5) synaptogenesis
6) synapse elimination
191
what is gastrulation?
cell specification into three distinct layers
192
what is neurulation?
specification of neural tissue
193
what is neurogenesis?
amplification of cell number
194
what is Neural Specialization?
major brain divisions created by fate specification and differentiation
195
what is synaptogenesis?
formation of synapses
196
what is synapse elimination?
refinement of circuits
197
what are the three cell layers of the blastocyst?
1) endoderm
2) mesoderm
3) ectoderm
198
what is the endoderm?
becomes the innermost layer of the embryo and
| produces the digestive tube and its associated organs (including the lungs)
199
what is the mesoderm?
becomes sandwiched between the endoderm and ectoderm.
generates the blood, heart, kidney, gonads, bones, and connective tissues
200
what is the ectoderm?
generates the outer layer of the embryo
produces the surface layer (epidermis) of the skin and forms the nerves
forms the brain! (neural tissue)
201
what do the mesodermal cells do?
Mesodermal cells secrete proteins (under control of the BMP4 gene) that induce some of the ectodermal cells to become neuroectoderm
All cells in the adult nervous system come from these neuroectodermal cells
202
what is neurulation?
neuroectoderm --> neural fold --> neural plate --> neural tube (which eventually closes along the entire dorsal-ventral axis of the body)
203
what is neurogenesis?
proliferation of neurons through cell division
The number of neurons is determined by the Notch gene
Due to TGF beta, neurogenesis does not occur evenly along the neural tube (which is sort of why the spinal cord is long and thin and the brain is big)
204
what is neural specialization?
Embryonically, there are major subdivision of the brain:
- These structures will functionally divide mature brain regions
- There is a large degree of sublevel differentiation in a mature brain
early embryo structures don’t have much differenciation at the lower levels
205
what is neural specialization in embryogenesis?
3 parts subdivide until they become subdifferentiated into 5 parts
forebrain, midbrain, hindbrain --> telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon
206
how do neurons communicate with each other?
at the synapses - between the presynaptic and postsynaptic neurons
207
what are the steps of synaptogenesis?
1) target finding (via chemotaxis: a synapse needs to find its target: the interneuron sends out a chemical gradient)
2) target signaling to create synapse: the target seeker fires a signal and if it’s the correct signal then they’ll respond by forming an immature connection
3) real synapse that secretes neurotransmitters: then there becomes a feedback loop - every time you use that same connection it becomes stronger
208
what is synapse elimination?
synapses don't make you smart
At birth, too many neurons in what will become the auditory cortex are linked to the visual area
Observed changes in synaptic density does not support "directed" synaptogenesis --> it’s tempting to think that our synapses form in anticipation of what they’re going to be used for
209
experience in relation to the number of synapses a person has
experience doesn’t create new neurons - it just decides which neurons get to be kept - causes selective survival of certain synapses
Rakic
210
genes shared by all humans...
lay down the basic pattern of the brain.
211
what is epigenetic?
the study of stables changes in gene expression that are mediated by the environment
the amount of stress that mothers reported experiencing during their children's infancy was related to the amount of methylation in the children's genomes 15 years later
212
what is the theory of cognitive development?
stage theory
Jean Piaget's
the development of thinking and reasoning
water amount in differently shaped glasses
213
what are the three ways that researchers obtain data about children?
1) interviews
2) naturalistic observation
3) structured observation
214
what are structured interviews?
useful when the goal is to collect self-reporters on the same topics from everyone being studied
215
what's a clinical interview?
useful for obtaining in-depth information about an individual child
interview begins with a set of prepared questions but if the kid says something interesting they'll branch off
tailored for a specific person
216
what is naturalistic observation?
when the primary goal is to describe how children behave in their usual environments
observers try to remain unobtrusively in the background in the chosen setting allowing them to see the relevant behaviors while minimizing the chances that their presence will influence those behaviors
difficult to know which aspects of situations are most influential
217
what is structured observation?
researchers design a situation that will elicit behavior that is relevant to a hypothesis and then observe how different children behave in that situation - the research then relate the observed behaviors to characteristics of the child such as age, sex, personality
insures that all children being studied encounter identical situations - allows for direct comparison of behavior in a given situation
218
genes, chromosomes and dna
genes make up chromosomes which make up DNA
219
how many chromosomes does a cell have?
46 - 23 pairs
sex cells only have 23 chromosomes
220
what is mutuation?
a change that occurs in a section of DNA
causes genetic diversity among people
some mutations are random, spontaneous errors; others are caused by the environmental factors
usually harmful
221
what causes diversity among people?
1) mutations
| 2) random assortment of chromosomes in the formation of egg and sperm
222
what is crossing over?
when germ cells divide, the two members of a pair of chromosomes sometimes swap sections of DNA = some of the chromosomes that parents passed on to their offspring are constituted differently from their own
223
what are regulator genes?
the switching on and off of genes is controlled primarily by regulator genes
external factors can affect the switching on and off of genes
224
what is methylation?
the silence of gene expression
epigenetics: the stable changes in gene expression that are mediated by the environment involve methylation
225
what are multifactorial traits?
traits that are affected by a host of environmental factors as well as genetic ones
226
what are neurons?
cells specialized for sending and receiving messages between the brain and all parts of the body as well as within the brain itself
227
what are sensory neurons?
transmit information from sensory receptors that detect stimuli in the external environment or within the body itself
228
what are interneurons?
act as intermediaries between sensory and motor neurons
229
what are the three parts of neurons?
1) cell body
2) dendrites
3) axon
grey matter of the brain
230
what are cell bodies?
contain the basic biological material that keeps the neuron functioning
231
what are dendrites?
fibers that receive input from other cells and conduct it towards the cell body in the form of electrical impulses
232
what is the axon?
a fiber that conducts electrical signals away from the cell body to connections with other nuerons
233
how do neurons communicate?
at the synapse
234
what are glial cells?
white matter of the brain
form the myelin sheath around axons
form and strengthen synapses
235
what is the myelin sheath?
it surrounds axons and insults them and increases the speed and efficiency of information transmission
236
what is the temporal lob associated with?
memory, visual recognition, speech and language, processing of emotion and auditory infomration
237
what does the parietal lobe do?
spatial processing
| integrating sensory input with information stored in memory
238
what is the corpus callous?
the left and right hemispheres of the brain communicate with each other primary through it
239
what is cerebral laterilzation?
the two hemispheres of the brain are specialized for different modes of processing
240
what are secular trends?
marked changes in physical development that have occurred over generations
kids are way taller than their same sex grandparents
