PSYC 331: Ch 5: Seeing, Thinking, Doing

-Testing infants

-how do we get infants to tell us what they know?

-high amplitude sucking

-looking

-brain responses

-high amplitude sucking paradigm; measures rate at which infants suck on special pacifiers

-infants suck faster when interested in something, slower when bored

-access to preferred stimulus can also be made dependent on sucking rate

-babies language preferences at birth

-looking time: infants look at things they like, or think are interesting/surprising

-the longer an infant looks at something, the more they are interested in it

-preferential-looking: infants will look at the thing they find more interesting

-researchers can use this to infer whether children recognize changes or differences in stimuli

-Pascalis et al, 2002

-habituation: boredom in response to a repeated stimuli demonstrates infant learning, followed by increased attention to a new stimulus

-researchers can use this to infer whether children recognize changes or find something surprising

-Pascalis et al., 2002

-question: perceptual narrowing for (non)n=human faces?

-PN = change in perception ability due to synaptic pruning

-tested 6 month olds and 9 month olds (and adults) recognition of monkey faces (human faces too)

-idea: younger kids should do better b/c no PN yet for them

-habituated kids to specific monkey faces

-used VPC to test recognition of familiar vs. novel faces

-idea: kids should look longer at new faces (new = interesting)

-results: only 6 month olds looked longer at new faces

-brain responses: we can measure changes in brain activity to stimuli

-Perception

-infant vision

-infants are born extremely myopic (nearsighted)

-vision is best 6-9 inches away

-but, vision improves rapidly- by 8 months it is almost adult-like. 

-poor contrast sensitivity so they prefer to look at high contrast objects

-newborns also have poor color vision (until about 3 months)

-bc their cones are the wrong shape and length, and are less densely packed at the fovea

-object segregation: identification of different objects in the visual field

-perceptual constancy: perceiving an object as unchanging eveen when viewed under varying conditions

-as objects move away they get smaller, but seem unchanged besides the distance

-depth cues: 

-first few weeks: kinetic cues, visual expansion, motion parallax: further thing pass by slower

-4 months: binocular disparity

-7 months: pictorial cues: monocular depth cues

-Motor Development

-sucking

-rooting

-grasping

-stepping

-babinski

-moro

-tonic-neck

-Motor Milestones

-with each milestone, there are gains and advantages

-perspective

-independence

-these lead to increased exposure and learning

-1 month: lift their chin

-2 month: push up with hands

-4-5 months: sit with support

-6 months: roll from back to stomach and vice versa

-7 months: begin sitting up on their own

-8.5 months: crawling (knees and hands)

-9.5 months: creeping (feet and hands)

-10 months: standing with support, standing UP with support, stepping with support

-12 months: first steps

-15 months: walking by themselves

-2 yrs: climb steps one at a time, run, jump, walk backwards, kick a ball…

-Culture in motor development

-cultural differences in exposure to locomotion

-leads to small differences in acquisition

-differences in physiological maturation

-overall, children from different cultures reach milestones at roughly the same time, with some small variation

-Specificity of motor learning

-infants learn to crawl, walk, climb stairs and ramps

-must learn to their gauge abilities in each modality

-learning in each type of locomotion is specific to that modality (doesn’t generalize)

-children must master each skill separately

-Experience broadens perception

-”Visual Cliff” experiment

-novice crawlers didn’t fear cliff, were willing to crawl over

-experienced crawlers refused to cross cliff

-fear of heights develop with age/experience

-scale errors

-Errors related to sizing and interacting with objects

-children learn how to interact with their world, but don’t always get it right

-”Sticky mittens”

-velcro gloves allow infants to pick up objects

-experience increased: 

-interest in objects

-object exploration and reaching

-interest in social partners

-Learning

-operant learning: infant learns its actions have outcomes

-contingency paradigm: reward is made dependent on infants’ actions

-2-month-olds learned to control the mobile

-Observational learning

-tongue protrusion study: stuck tongue out of newborn, newborn stuck tongue back out

-children imitate, and learn through observation

-”Light Box Study”

-infants imitated the actions of an adult after a delay

-evidence of deferred imitation

-Dumbbell study

-18 month old infants watched an adult fail to pull apart a dumbbell toy

-when given the you, children happily pulled it apart themselves

-but, they did not do so when a robot failed to do it

-Cognition

-violation of expectancy

-infants habituated to a board rotating 180 degrees back and forth

-then an object was placed in its path

-infants saw the board hit the object OR pass right through it

-after 3.5 months of age, infants looked longer at the “impossible event”

-suggests that infants have knowledge of object properties

-early social cognition

-infants habituated to hand reaching for one toy

-then saw the hand reach for the same object or to the same location

-were more surprised to see reach to the same location

-6-months olds interpret actions as goal-directed

-helpers and hinderers

-children preferred helping characters

-young infants also have some understanding of social traits