Blakemore & Cooper (1970)

Question 1

Blakemore & Cooper aims?

Answer 1

investigate development of primary visual cortex (in cats)

find out if properties e.g. orientation = innate (as suggested by Hubel + Weisel) or learned

Question 2

Blakemore & Cooper research method?

Answer 2

lab experiment

Question 3

Blakemore & Cooper design?

Answer 3

independent measures

Question 4

Blakemore & Cooper IV?

Answer 4

whether kittens reared in horizontal or vertical environment

Question 5

Blakemore & Cooper DV?

Answer 5

whether vertical condition kittens could detect horizontally aligned objects and vice versa

Question 6

Blakemore & cooper sample?

Answer 6

kittens
randomly allocated to 2 conditions
2 (1 horizontal condition, 1 vertical condition) used to study neurophysical effects

Question 7

Blakemore & Cooper procedure?

Answer 7

kept in completely dark room from birth

age 2 weeks onwards - about 5 hours per day put on clear glass platform inside tall cylinder covered in black-and-white stripes either vertical or horizontal
wide black collar - restricted visual field to width of about 130 degrees, could not see body

stopped being put in cylinder at 5 months old (beyond ‘critical period’ in which total visual deprivation causes physiological deficits according to Hubel & Weisel (1970))
several hours each week in small, well-lit room with tables and chairs in it
visual reactions observed + recorded

7.5 months 2 kittens anaesthetised + their neurophysiology examined

Question 8

Blakemore & Cooper key findings?

Answer 8

initially extremely visually impaired:
‘behavioural blindness’ - horizontal condition could not detect vertically aligned objects + vice versa

within 10 hours vision mostly back to normal

permanent defects:
follow moving objects with clumsy, jerky head movements
tried to touch things moving on other side of room, well beyond reach

neurophysiological examination:
no evidence of sever astigmatism
vertical condition, horizontal plane recognition cells did not ‘fire-off’ and vice versa
75% cells in both cats = binocular + in almost every way responses = normal
no obvious large regions ‘silent’ cortex corresponding to ‘missing’ cortical columns observed

Question 9

Blakemore & Cooper possible conclusions?

Answer 9

kitten’s visual experiences can change brain + perceptual consequences

kitten’s visual cortex changes with age + visual experiences

kitten’s nervous system adapts according to visual input

kitten’s brain development determined by functions carrie out, not genes

kitten’s environment can determine perception at behavioural + physiological level