Lecture 5 - Perceptual and motor development

Question 1

Perception and VEP (visual evoked potential)?

Answer 1

• visual processing takes over half our brains
• the scalp activity recorded as a result of visual stimuli is called ‘visual evoked potentials’

Question 2

How do you measure VEP?

Answer 2

by attaching electrodes to a persons head

Question 3

Orientation perception?

Answer 3

• Braddick found cortical orientation develops as early as 3 weeks
• by 5 weeks we show strong evidence of orientation perception

Question 4

Motion looming?

Answer 4

• when an object looms towards you it might be some kind of threat
• when we perceive a physical threat we may want to take some defensive action
• an instinctive action to take is blinking

Question 5

Yonas et al?

Answer 5

• tracked whether infants blink to avoid collision from 1-9 months
• found they start doing this from about 4 months but not before

Question 6

Orioli et al?

Answer 6

• measure looming in a preferential looking paradigm in infants between 14 and 94 hours old
• 1 condition had an incoming and receding object, the other had 2 objects approaching or 2 objects approaching and not colliding
• results showed longer looking to approaching object in exp 1 and longer looking to colliding vs non colliding in exp 2

Question 7

Wattam-Bell?

Answer 7

• compared same direction movement with direction change
• responses to directional motion emerge at 10 weeks for low speeds and 13 weeks for high speeds

Question 8

Depth perception - Gibson and Walk?

Answer 8

• wanted to test whether depth is innate
• asked infants to crawl over a visual cliff or come away from it to the shallow side
• 92% refused to cross the cliff
• criticisms: baby has to be old enough to crawl, ethical issues

Question 9

What is stereopsis?

Answer 9

the perception of depth through noticing differences between the images in the 2 eyes (‘binocular disparity’)

Question 10

Braddick and Atkinson?

Answer 10

• compared perpetual depth changes in infants wearing either red-green or red-red glasses
• red green should give different messages to the brain

Question 11

What is motor development?

Answer 11

• the emergence of the ability to execute physical actions such as reaching, grasping, crawling and walking
• is done in stages and there are lots of cultural variations

Question 12

What view is held by Thelen and later by Adolph?

Answer 12

• idea that motor abilities are present earlier than previously thought
• however there expression is limited by other factors e.g. physical development, experience with motor programs

Question 13

The visual cliff?

Answer 13

• at 7-8 months the visual cliff is avoided by 35% of inexperienced crawlers and 65% of experienced crawlers
• experience is necessary for learning the visual cues to depth and feeding them into motor plans
• but experience may not be necessary in non-humans