Child Psychology 560 Infant Sensation Perception and Learning 2 02 11 2014 Infant Visual Perception What can babies see And how do we know Methods o o o Habituation boring them Sucking Looking Preferential responses Looking Listening Psychophysiology Heart rate decrease more interest EEG and ERP Newborn Visual System Not that great at birth Acuity sharpness of vision o o o o Very low at birth 20 120 Quickly Developing By 8 months 20 30 Test Acuity using preferential looking What do babies look at o Newborns focus on 1 point o Sticky perception trouble disengaging As motor control improves Eyes move together around 3 4 months Smooth pursuit of moving objects 7 month old tracking moving shapes o Cool Color Vision A lot of toys marketed to newborns are black and white Can t see color very well at beginning but can tell contrast o 1 month old high contrast Faces focus on contrast o 1 month old scans outermost parts of face o Babies like faces because they have a lot of contrast 2 month old more scanning internal features Are faces special for infants video o Can infants recognize faces Not hardwired from birth Attracted by face like configurations more than other shapes By 8 months can tell when face is normal or upside down Different patterns of brain activity Face Preferences o Mother caregiver preference Newborns prefer mom s face But not if mom wears scarf Preferential looking Loss of contrast Prefer faces of caregiver s gender o Not just females over males Prefer attractive faces Other Race Effect ORE 3 month olds prefer own race faces Newborns don t though By 9 months have difficulty discriminating between faces of other races Other Race Effect But not really own race Caregivers race o Other Species Effect Adults and 9 months old can t discriminate monkey faces 6 month old infants can o o 3 month old babies of African emigrants to Israel equally interested in African and White faces Still open minded haven t been nurtured yet by experience Perceptual narrowing Phenomena that we start off very open minded but narrow though experience due to our environment and what is important in our environment Baby cam video Put camera on baby to see what they re looking at Saw faces 25 of the time Object segregation How many objects are on this table Can babies segregate objects how What Counts as an Object Kellman and Spelke 1983 4 month olds o Habitual stimuli a o o Whole rod Broken rod Do they think that what is back there is a whole rod or broken o o Rod partially hidden by a block Moving or still Test stimuli b o o Pg 193 hint on exam If they realize what they are seeing is whole rod covered by block then broken rod should be more interesting from dishabituating If they think 2 pieces whole rod should be more interesting Results o Habituation to moving rod o Habituation to still rod o No preference Moving together one object o Prefer broken rod Even if two ends look different Not in newborns Learned First seen in 2 month olds Depth Perception 1 month olds blink to looming objects o Optical expansion Maturational o Preterm infants blink to looming objects later Experience o o Stereopsis 2 eyes converge for 1 image with depth Not until 4 months Newborns eyes move in same direction only half the time Experience require Hubel Weisel Monocular deprivation precludes stereopsis Testing Depth Perception The visual cliff Gibson Walk o o o Climbing across plexiglass towards mom that looks like cliff Glass is invisible have parent on other side calling the baby see if they have depth perception yet or not Results 6 to 14 month olds won t cross deep side 1 5 month olds detect depth but unafraid Heart rate deceleration Experience dependent How much they have crawled can be a factor Animals that walk after birth avoid deep end at 1 day Experience in walker more wary of cliff Experience with clear objects cross early Does appear to be experience dependent 02 11 2014 02 11 2014