Chapter 5 Perception I Seeing Thinking and Doing in Infancy A Definitions 1 Sensation 2 Perception B Vision a Sensory processing of information via organs of sensation ears eyes nose etc a Organization and analyzation of inputted sensory information 1 Preferential looking technique a Research method that times how long an infant looks at an object 2 Visual Acuity a The clarity of infants vision b Very low at birth 20 120 c Much better at 8 months of age 20 30 d Contrast sensitivity i Infants have difficulty distinguishing between two non contrasting colors ii Caused by immaturity of cones in infants eyes Cones enable color vision Color vision is developed by 2 3 months e Acuity is fully developed by 6 years of age f Tested using preferential looking 3 Visual Scanning a Sticky perception i Newborns have trouble moving their eyes to specific spot b Newborns have great difficulty controlling eye movements i Can begin to visually track objects at 3 months of age ii Aka smooth pursuit c Perception of faces i Newborns tend to look at the outline and high contrast features of a face or object as opposed to the object as a whole ii By two months infants begin looking at more internal parts of objects color vision is enabled allowing for perception of low contrast areas iii Predetermined ability to distinguish faces over other objects are innate but development of ability is controlled by experience iv Newborns prefer mom s face over an unfamiliar woman s v Infants prefer faces of caregiver s gender vi Infants prefer attractive faces vii Other Race Effect ORE More difficult to distinguish faces of races one is not a part of or exposed to 9 month olds experience ORE 3 month olds prefer race of primary caregiver Newborns show no preference between races Other Species Effect Anyone over 9 months of age cannot discriminate between two different monkey faces 6 month olds can discriminate between the two Perceptual narrowing Phenomenon of being able to perceive in particular ways in early childhood but those abilities are lost due to experience 4 Pattern Perception a b Infants experience integrative vision i Can infer patterns based on provided stimuli Infants experience phi phenomenon the same way as adults 5 Object Perception a Perceptual constancy i Perception of a constant shape and size of an object ii Visual experience is not necessary to develop constancy b Object segregation i Perception of separate objects in a visual field ii Detecting the visual boundaries of objects iii Effect of movement Independent motion conveys separation of objects even to an infant No motion conveys no information to determine whether or not objects are separated Common motion conveys conjunction of objects Still true even if two visible portions of object or two exposed objects appear different 6 Depth Perception a Optical expansion i Phenomenon of an object s apparent increase in size as it approaches the viewer ii Present in infants as young as 1 month b Binocular disparity i Aka retinal disparity ii Difference between two visual inputs being sent to the brain from each eye iii Stereopsis Visual cortex computes the degree of disparity and forms perception of depth Begins developing around 4 months of age Newborns eyes only move in the same direction half of the time Experience required to develop c Monocular cues i Depth cues requiring only one eye ii Aka pictorial cues Relative size iii iv Relative motion v Interposition vi Convergence d Testing i Visual cliff Tests presence of depth perception Experience dependent 6 14 month olds won t cross Plexiglas side 1 5 month olds detect the depth change but are unafraid Corresponds to amount of experience walking crawling Infants who have experience with Plexiglas objects are less wary of cliff 7 Ramifications of Visual Challenges a Strabismus lazy eye i Sensitive period for binocular vision ii Dominant eye is patched to allow weaker eye a chance to catch up b Congenital cataracts reversible i Project Prakash ii Sensitive period for object perception iii No sensitive period for cross modal perception Learning period required to experience cross modal perception C Auditory Perception 1 Auditory localization a Estimated location of source of a sound 2 Music Perception a b Infants response to music is similar to that of adults Infants can perceive the difference between consonance and dissonance in music i Infants have perfect pitch c Can remember pieces of music over an elongated period a few weeks d Have innate perception of rhythm e Infants are able to recognize melodies beginning at 5 months of age D Taste and Smell of another woman 1 Newborns have preference for sweet tastes over other tastes 2 Newborns can also distinguish between the smell of their own mother and the smell E Touch 1 2 Starting around 4 months infants begin to transfer exploration duties to their hands Infants begin to experience touch through their mouth instead of their mouths 3 Sticky Mittens experiment conclusions 3 month olds Increased interest in objects a b Earlier reaching to objects c Increased interest in faces F Intermodal Perception 1 Aka Cross Modal perception 2 Combining of information from multiple sensory systems 3 Piaget months of age 4 McGurk Effect a Visual input alters speech perception b Infants show McGurk effect by 5 months of age 5 Modern theory a Claimed infants do not start to form associations between senses until a few a Newborns instinct to look towards a sound indicates association of visual and b aural sensory information Infants create visual picture of an object by using their mouth and can recognize an object after sucking on it even if it was not physically seen i Meltzoff pacifier study 2 pacifiers 1 smooth 1 knobby Control group breast fed infants Newborns preferred picture of familiar pacifier even though they hadn t seen it before experiencing it orally c Infants readily associate visual and aural stimuli as in watching a video i Spelke visual auditory matching study Two screens playing two different films of bouncing animals at different speeds Soundtrack matching only one film Infants 4 month olds preferred matching film ii 4 month olds are able to perceive when a voice soundtrack is aligned with a video of a person speaking and when it is not iii Infants can perceive emotion through tone of voice by 5 months of age II Motor Development A Reflexes 1 Grasping 2 Rooting cheek is touched 3 Sucking swallowing swallowing 4 Tonic neck 5 Stepping a Gripping