chapter 5: perception, knowledge and action in infancy Flashcards
cognitive development
the development of behaviors related to perception, attention, thinking, remembering and problem-solving
mental representations
an internal description of aspects of reality that persist in the absence of these aspects of reality
visual acuity and level at birth
the ability to make fine discriminations between the elements in the visual array, 1/30 of perfect vision at adulthood
visual accomodation and level in infancy
the ability to focus on objects irrespective of their distance to the eye, poor
when do acuity and accomodation improve
in the first 6 months
how can perception in infancy be studies
visual preference method or habituation techniques
visual preference method
infants are shown two objects side by side, the amount of time they spend looking at each one is compared - implies discrimination
habituation techniques
the process by which attention to a stimulus gradually declines over time and recovers when a new stimuli is presented
shape perception in newborns
capable of perceiving differences between simple shapes (cross, triangle, square, circle)
problems for infant perception
they might be discriminating between the forms on the basis of the presence of a single feature in one stimulus and its absence in others
experiments for perception in newborns - what are they discriminating actually
can discriminate between line orientations, 4-month-olds could discriminate on the basis of angular relationships but at 6-weeks couldn’t
size constancy
understanding that an object remains the same size despite its retinal image size changing as it moves closer to or away from us
shape constancy
understanding that an object remains the same shape even though its retinal image shape changes when it’s viewed from different angles
experiment with size constancy
newborns look longer at an object of different size than at the same object at a new distance even when the new object is placed at a distance that leads to the same retinal image - respond to true change in size
retinal image size
the size of visually perceived object on the retina of the eyes, will vary depending on the real size of the object and its distance from the observer
object unity
understanding that an object is whole or complete even though part of it may be hidden
experiment with object unity
habituated 4-month-olds to rod moving back and forth behind the box, looked longer at separate parts - only when the rod moves (common motion)
at 2 months - only showed the same results if the occluding box was made narrow
when can newborns show object unity
when the stimuli are presented stroboscopically
object moves behind an occlude experiment
habituating infants to an event in which an object moved back and forth disappearing behind an occlude in the central part of its trajectory
6 months - perceive it as continuous
4 months - only when the occlude was narrow or the object was out of sight very briefly
2 months - perceive it as discontinuous
subjective contour
when only parts of an object are presented, the remaining contours are filled in, in order that the complete shape can be perceived
subjective contour experiment
habituated to a subjective contours of a square and then measuring looking at a real square vs other object
doesn’t exist at birth but does 4+ months
face perception experiment
facial features in the right places vs in a jumbled array vs no features but same overall brightness
preference for face in the 1st month
criticism - facial arrangement contained more info around the edges
later for 2 and 4 months
what happened when they moved schematic stimuli int he visual field of newborns
followed faces longer and further
what are the two mechanisms behind face preference
two process account - innate subcortical mechanism (CONSPEC) that leads them to attend preferentially to facies of the same species + after second month - CONLERN - specialization
preference for certain properties of stimuli that aren’t face specific (top heavy stimuli)
difficulties of face discrimination experiments with infants and how were they combated
also able to identify their mothers by the sense of smell (perfume) and the mother also recognizes her child (videotapes)
when are newborns capable of discriminating between the mother’s and female stranger’s face
within days of birth
attractiveness bias in infants explained
the prototypical face (attractive) might trigger the face recognition system
until when are babies able to discriminate Barbary macaque monkeys
can at 6 months not at 9
when can infants discriminate other races and infant faces
at 3 months can’t by 9
when is preference for female faces found
by 3 months, only for the same race + male for those with male caregivers
what did Piaget say about imitation
impossible until infants are capable of representing self and others (late in infancy_
how was imitation studied
blind raters asked to identify the gesture made by the infant as matching the one the adult had been modeling
when do infants prenatally start responding to auditory stimuli
at 26 their heart rate is changed in relation to auditory stimuli, respond at 12 weeks
what other animals can make similar speech sound discrimination to very young infants
chinchilla rabbits
cognition
psychological processes that involve mental representations and thus that go beyond perception
object permanence
the ability to understand that even if an object is no longer visible, it continues to exist
what did Piaget say, when did development of mental representations happen
not before 9 months
when can children solve the A not B error
8-12 months
violation of expectation technique
infants are shown an event and are then shown two new events, now of which is possible and one of which isn’t - typically look longer at the impossible one
flap violation experiment
5 months - familiarized with a repeated event in which a flap rotated from flat on the table through 180 degrees so that was again flat on the table
possible - the flap rotated to hide a block and stopped
impossible - the flap rotated 180 degrees appearing to move through the block (more similar to the original event) - looked longer
truck violation experiment
familiarized with an event in which a truck ran down a track and passed behind a screen
possible: a block is placed behind the track
impossible: block on the track which the truck just passes
infants at 6 and 8 months - looked longer at the impossible event + at 4 months
ball roll violation experiment
2-month-olds familiarized to an event in which a ball rolled behind a screen, the screen was raised to show the ball resting against an end wall
possible - screen lifted to show a ball next to the obstruction
impossible - ball beyond the obstruction - looked longer
the top of the obstruction was visible, not full object permanence
core knowledge
basic information about the world, about the physical properties of object available to the very young infant, possibly innaate
two types of moving object events experiment
familiarized infants at 3 and 4 months to them
in both - 2 screens present, continuous event, an object moved behind the first screen and showed up from it, disappeared behind the second one and showed up again + discontinuous - the middle segment of the object’ trajectory was omitted, disappeared behind the first screen and an identical object showed up after a delay
those familiarized with the continuous movement looked longer at the two objects and the other way around
width of the screen experiment
at 7 and 9 months - shown a moving object event in which an object disappeared behind a screen and a different one emerged from the other side
looked longer when the screen was too narrow for both objects
subitising
the ability to perceive directly the number of items without consciously counting them or using another form of calculation
subitising experiment in infants
habituated 4 to 7 month old infants to patterns of certain number of dots (2 or 3) and then tested for dishabituation to the other number and a large number condition - dishabituated to the number change
hand moving objects experiment
infants at 4 and 5 months presented with a single object, a screen hid it, a hand appeared with a second object and placed it behind the screen or took one away if there was 2 in the beginning- looked longer at what wasn’t expected
also looked longer when presented with 1+1 but got 3 objects
will infants look for an object under a transparent cup
yes, even if they failed when the cup wasn’t transparent - only problem is when one object conceals another, difficulty understanding the relationship between the object and the occlude
response perseveration
repeating a previously learned response usually when it’s no longer appropriate
memory theory for A not B
infants rarely made errors if they were allowed to look for the object immediately at B - interference occurred between memory of the object at the first location and memory of it at the second location
problem with the memory theory for A not B
errors occurred even when the object was fully in view at the B location + errors when the object was placed under a transparent cover at B
A as a container explanation
infants might be exploring place A for further objects - treat A as a container
dogs vs wolves A not B (why does this exist)
wolves didn’t make errors on B trials but dogs did in communicative conditions, improved in non-communicative conditions
attention A not B theory
when attention is distracted during the delay, perseveration behaviors increased
longer looks and larger % of time spent looking during a focal attention task correlated with success on the AB task
connection between A not B and SES
low SES - delayed development on the task, high SES - higher overall attention, greater increases in attention to complex stimuli
frontal cortex
involved in emotional experiences and many cognitive abilities
executive functions
the process whereby behavior is directed and controlled in order that the desired goal will be achieved
AB task and EEG activation
association, but difficult because infant movements can interfere with EEG
resting EEG might not be valid - maybe those with lower resting activity show a larger increase in activation
did infants who made AB errors show evidence of knowing where the object was
yes, looked longer