Task 2 Wonder baby

Question 1

Preferential-looking technique

Answer 1

o Studying visual attention in infants
o Two different stimuli are presented side by side screens, when the infant looks longer at one of the stimuli the researcher can infer that the baby is able to discriminate between them and has a preference for one over the other

Question 2

Habituation

Answer 2

o The infant is presented to a stimulus over and over until they get used to it. Then they are shown a novel stimulus. If the response of the infant increases, the researcher can infer that the baby discriminate between the old and the new stimulus.

Question 3

Paired comparison

Answer 3

o A stimulus is presented during a familiarization period. Then during the recognition period, this now familiar stimulus is presented with new stimulus that the infants have never seen before, the amount of time the infant looks at each stimulus is measured, because infants tent to look at novel stimulus shows that they can distinguish faces

Question 4

Visual evoked potential (VEP)

Answer 4

o Measuring acuity involves measuring an electrical response
o Is recorded by disk electrodes placed on the back of the infants head above the visual cortex.
o The infant looks at a grey field, which is briefly replaced by either a grating or checkboard pattern. If the stripes ore checks are large enough to be detected by the visual system, the visual cortex generates an electric response called the visual exposed potential
o The VEP provides an objective measure of the visual system’s ability to detect details

Question 5

Contrast sensitivity functions (CSF)

Answer 5

Determining the contrast sensitivity of gratings with different spatial frequencies results in a plot of contrast sensitivity versus spatial frequency
o Contrast Sensitivity: is measured by determining the smallest difference between the dark and light bars of a grating at which an observer can still detect the bars
o Spatial frequency: the number of cycles of the grating (in which cycle is one bar and one dark bar)
 Depends on the distance of the observer as well

Question 6

Infants vision

Answer 6

o Perceiving the world visually directly after leaving the womb
o Infants have poor contrast sensitivity: they can detect a pattern only when it is composed of highly contrasting elements.
 This is because of the different size and shape and the bigger distance between them
o They catch only 2% of the light striking the fovea compared to 65% in adult
o Full acuity is reached at a age of 6
o 2-3 moths of age the colour vision is similar the one of adults
o Infants are more likely to track objects that are moving
o Infants (younger than 2 months) tend to focus only on the perimeters because the contrast is the highest at this point
o Infants prefer moving light depiction of biological motion over one of nonbiological motion

Question 7

Acuity of infants

Answer 7

 1 month: about 20/400 to 20/600 means an infant must view from 20 feet to see the same what an adult can see from 400 feet
 Increases rapidly over the first 6 to 9 months
 1 year: full acuity is reached

Question 8

Perceptual constancy (Object perception)

Answer 8

the perception of objects as being of constant size, shape, colour, etc., in spite of physical differences in the retinal image of the object, visual experience is not necessary to perceive this, so infants are able to perceive this

Question 9

Object segregation (Object perception)

Answer 9

the identification of separate objects in visual array
• Infants learn this because of movement, e.g. when you pick up a cup from a plate, they see that both are independent objects (common movement)
• They also use physical properties at an age of 4 ½ month when they are familiar with the object

Question 10

Optical expansion (depth perception)

Answer 10

a depth cue in which an object shadows increasingly more of the background, indicating that the object is approaching (3 months)
• Infants blink if it looks like its approaching them (1 month)

Question 11

Binocular disparity (depth perception)

Answer 11

 Binocular disparity: the difference between the retinal image of an object in each eye that results in two slightly different signals being sent to the brain, the closer the object the bigger the disparity (3-6 month)
• Binocular fixation: the two eyes are both looking directly at the object and the two fovea’s are therefore directed at the same place (3 month)

Question 12

Stereopsis (depth perception)

Answer 12

the process by which the visual cortex combines the differing neural signals caused by binocular disparity, resulting in perception of depth (4 month)

Question 13

Monocular depth cues (depth perception)

Answer 13

The perceptual cues of depth (such as relative size and interposition) that can be perceived by one eye alone (6-7 month)

Question 14

Perceiving colour

Answer 14

 Develops within the first 3 to 4 months

Question 15

Taste and smell

Answer 15

o Taste and smell develop before birth and new-borns prefer sweet flavours.
o Can discriminate sweet, sour and bitter stimuli

Question 16

Hearing

Answer 16

o inner ear is already fully developed
o at an age of 6-month hearing is fully developed
o infants can recognize their mothers voice after 2 days

Question 17

Intermodal perception

Answer 17

the combining of information from two or more sensory systems
• Starts already very early
• Between 5-7 months infants notice the connection between emotional expression in faces and voices
• 4 months: able to recognize lip synchrony

Question 18

Article

Answer 18

 Infants did cross cliff even in face-only condition
 May not use facial-only cues to guide their behaviour in ambiguous situations but they do so in potentially threatening situations
 Infants crossed faster in response to vocal-only than facial-only cues
 Voice more potent channel of emotional communication than face
 More powerful modifier of infant behaviour
 Crossed equally fast in face-plus-voice and voice-only conditions
 Facial cues did not significantly increase potency of the signal
 Infants looked to mother equally in face and voice-only conditions
 Weren’t necessarily social referencing looks to gather information
Why?
 Infants commonly receive vocal without accompanying facial cues
 Learn to trust & respond appropriately to voice so don’t need facial cues to social reference
 Don’t lose time as they don’t need to seek out voice (like face) to gather information
 Can assess novel sitch and visually focus while simultaneously gathering auditory information
 When infants cannot determine referee’s gaze-direction, they nevertheless resourcefully use vocal cues to modify behaviour
 Usually use adults gaze to determine which object to link to adult’s emotional outbursts)
 Instrumental referencing more effective than affective referencing (face = affective, voice = both)

Question 19

social referencing

Answer 19

process of communication whereby people actively seek and use others’ perceptions and interpretations of ambiguous situations to form their own interpretations of those situations
 Instrumental social referencing – messages explicitly convey what infants should
 Affective social referencing – messages show infant what to feel
 Infants guide their behaviour based on emotional cues people offer them