Problem 2 - DONE

Question 1

vision

Answer 1

• visual acuity
• -> contrast sensitivity
• -> colour perception
• visual scanning
• pattern perception
• object perception
• depth perception

Question 2

visual acuity

Answer 2

• sharpness of visual discrimination –> how clearly one can see
• contrast sensitivity
• colour perception
• methods: preferential looking and visual evoked potential

Question 3

contrast sensitivity

Answer 3

• ability to detect differences in light and dark areas in a visual pattern
• by determining smallest difference between dark and light bars of a grating, at which an observer can still detect the bars

–> reason: immaturity of infants’ cones

Question 4

colour perception

Answer 4

• develops early –> present within first 3 to 4 months of life
• method: habituation

Question 5

visual scanning

Answer 5

• start visually scanning environment right away
• tracking moving stimuli is difficult
• visual scanning is restricted

Question 6

pattern perception

Answer 6

• analysing and integrating the separate elements of visual display into a coherent pattern
• active integration of separate elements in stimulus —> into a single pattern
• coherence among moving elements

Question 7

object perception

Answer 7

• perceptual constancy = perception of objects as being of constant size, shape, colour, etc. in spite of physical differences in the retinal images of the object
• object segregation = identification of separate objects in a visual array

Question 8

face recognition (goldstein)

Answer 8

• preference for mother is so strong —> overrides usual tendency to prefer novel stimuli
• no clear evidence for face-sensitive mechanism

Question 9

depth perception

Answer 9

• depth and distance cues –> to navigate through our environment
• optical expansion = depth cue in which an object occludes increasingly more of the background, indicating that the object is approaching
• binocular disparity = difference between retinal image of an object in each eye that results in two slightly different signals being sent to the brain
• -> stereopsis
• monocular depth cues = pictorial cues = perceptual cues of depth (such as relative size and interposition) that can be perceived by one eye alone

Question 10

hearing

Answer 10

• at birth: well developed (relative to visual system); inner ear structures appear to be mature, conduction of sound through he outer parts is inefficient
• improvements in ear; auditory pathways in the brain mature
• -> other factors: auditory localisation = perception of spatial location of a sound source

Question 11

threshold and recognising mother’s voice (goldstein)

Answer 11

• 3 months: infants only occasionally heard the tone that was presented at low intensities or not at all; more likely at high intensity
• newborns recognise their mother’s voice –> they heard the mother talking during development in the womb

Question 12

music perception

Answer 12

• infant-directed singing
• music memory is surprisingly detailed
• consonant preference (like adults)
• melodic perception (unlike/better than adults)
• musical rhythm (unlike/better than adults)

Question 13

perceptual narrowing

Answer 13

• with experience perception is narrowed
• inexperienced infants detect more differences
• -> become attuned to patterns in biological and social stimuli that are important in their environment

Question 14

speech perception (goldstein)

Answer 14

• starting point for understanding speech perception: response to phonemes
• -> phonemes = smallest unit that when changed, changes the meaning of a word
• 1 month: capable of categorical perception
• 1 year: tuning of phonemes of the language to which they have been exposed

Question 15

olfaction and taste

Answer 15

• develops before birth
• -> taste: newborns can discriminate sweet, sour, bitter
• preferences taste: sweet flavours
• -> smell: how to learn to recognise their mothers; smell and discriminate
• preferences smell: breast milk (natural food source for human infants)

Question 16

touch

Answer 16

• important way to learn about their environment
• active touch —> through their mouth/tongue, later with hands and fingers
• oral exploration
• -> first few months
• -> infants mouth and suck on their own fingers and toes + any other object they come into contact with
• manual exploration
• -> around 4 months (with greater control over their hand/arm movements
• -> actively rub, finger, probe, bang objects —> actions become increasingly specific to properties of objects

Question 17

intermodal perception

Answer 17

• combining of information from two or more sensory systems

Question 18

methods for studying infant perception

Answer 18

• preferential-looking technique
• visual evoked potential technique
• habituation
• random-dot stereograms
• observer-based psychoacoustic procedure
• operant conditioning
• categorical perception experiment
• paired comparison

Question 19

methods - preferential-looking technique

Answer 19

• method for studying visual attention in infants
  1. two stimuli (patterns/objects) are presented at same time –> see where the infant is looking
  2. if one stimulus is more looked at than the other –> infant can tell the difference between them
• -> spontaneous looking preferences (prefer to look at certain types of stimuli)

–> determines visual acuity, recognition of mother’s face

Question 20

methods - visual evoked potential technique (VEP)

Answer 20

• method to measure electrical signals
  1. disk electrodes are over the visual cortex
• -> polled response of thousands of neurones that are near the electrode
  2. infant looks at grey field –> which is briefly replaced by either one of two patterns
  3. when the stripes/checks become large enough to be detected by visual system –> visual cortex creates VEP

–> objective measure of visual system’s ability to detect details; determines visual acuity

Question 21

methods - habituation

Answer 21

• method for studying sensory and perceptual development
  1. repeatedly presenting an infant with a particular stimulus –> until the infant’s response declines
  2. new stimulus is presented
• -> if response increases = infant can discriminate between the habituation stimulus and new stimulus
• -> dishabituation = increase in looking time when stimulus is changed (second stimulus appears different to infant)

–> determines colour perception; object unity perception; recognition

Question 22

methods - random-dot stereograms

Answer 22

1. presented with one picture to their right + another to their left eye –> see whether observer’s visual system can convert disparity information into perception of depth
   - -> stereopsis = process by which visual cortex combines differing neural signals caused by binocular disparity => perception of depth

–> (1) when infants can use binocular fixation to perceive depth

Question 23

methods - observer-based psychoacoustic procedure

Answer 23

1. infant is presented with a tone or not –> observer’s task is to decide whether or not the infant heard the tone
2. infant has earphones + the observer is watching the infant, out of his/her view

–> determines threshold for hearing a tone

Question 24

methods - operant conditioning

Answer 24

1. infants are given headphones –> either hear their mother’s or a stranger’s voice

–> determines whether infants recognise mother’s voice

Question 25

methods - categorical perception experiment

Answer 25

• method that determines phonetic boundary (= VOT when perception changes from one word to the other)
  1. experimenter vary the VOT and ask listeners what sound they hear
  2. even when VOT changed over a wide range –> listeners could only perceive two categories

–> determines phonetic boundaries

Question 26

methods - paired comparison

Answer 26

• method combining habituation + preferential looking
  1. familiarisation period, stimulus is presented
  2. recognition period, ‘familiar’ stimulus is presented together with a new one –> time infant looks at each stimulus is measured
• -> if they look longer at new face –> can tell the difference between two faces

–> determines ability of infants/adults to recognize human/monkey faces

Question 27

intermodal perception

article

Answer 27

• social referencing = process of communication whereby people actively seek and use others’ perception and interpretations of ambiguous situations –> to form own interpretations of those situations
• primarily considered a visual phenomenon
• classic visual cliff study –> human voice is a powerful modifier of infant behaviour in ambiguous + situations