Component 2: Blakemore and Cooper (Biological)

Question 1

What is Blakemoor and Coopers study about?

Answer 1

Sensory Restriction - Impacts of early visual experience.

Question 2

What is the background to Blakemoor and Cooper’s study?

Answer 2

Hirsch and Spinelli (1970) raised cats so that one eye was only ever exposed to horizontal stripes and the other to only vertical stripes. They analysed cells in the visual cortex and found that cells were now monocularly driven instead of binocularly-driven
Blakemoor and Cooper’s approach is slightly different in that they allowed the kittens normal binocular vision (both eyes used together) in an environment consistently of horizontal or vertical stripes.
Brains of humans and cats are similar in that both brains contain grey and white matter. Kittens brains have previously been shown to have brain plasticity.

Question 3

What is the aim of Blakemoor and Cooper’s study?

Answer 3

To investigate the physiological and behavioural effects of restricted early visual experience on the development of the cells in the visual cortex.

Question 4

What is the research method of Blakemoor and Cooper’s study?

Answer 4

Lab experiment (IV - whether the kittens were reared in horizontal or vertical environment DV- behaviour and neurophysical differences. Cells in the visual cortex were tested to see how they responded to lines of different orientations.

Question 5

What was the procedure of Blakemoor and Coopers study?

Answer 5

1. Kittens were housed from birth in a completely dark room.
2. From the age of two weeks they were put into special apparatus for an average of 5 hours a day.
3. The kittens stood on a clear glass platform inside a tall cylinder. Then entire inner surface was covered in high contrast black and white stripes (vertical or horizontal)
4. There were no corners in the environment and it could not see its own body as it wore a wide black collar
5. The kittens did not seem upset by the monotony of their surroundings and sat for long periods inspecting the tube walls.
6. This routine stopped when they were about five months old (well beyond the critical period)
7. The kittens were taken for several hours each week from their dark cage to a small, well-lit room, furnished with tables and chairs.
   Their visual reactions were seen/recorded
8. At 7.5 months the kittens were anaesthetised so their neurophysiology could be examined.

Question 6

What were the findings of Blakemoor and Cooper’s study?

Answer 6

Behavioural finding:
Permanent effects - followed moving objects very clumsily, reached for objects out of reach and bumped into things around a room.
Temporary effects - no startle response, at first extremely visually impaired, did not flinch at sudden movements, behavioural blindness; horizontally bred kittens could not detect vertical lines and vice versa, no evidence of visual placing - navigated through touch rather than sight (no depth perception)

Question 7

What were the conclusions of Blakemoor and Coopers study?

Answer 7

Nature (the brain) is modified by nurture (experience) so that the biological system fits demands of the environment.
The early visual experience of kittens can change their brains structure can have profound perceptual consequences
Both conclusions demonstrate brain plasticity.