blakemore and cooper (1970)- impact of early visual experience

Question 1

research method

Answer 1

This was a laboratory experiment which used an independent measures design.
• The independent variable (IV) was: whether the kittens were reared in a horizontal or a vertical environment.
• The dependent variable (DV) was their visuomotor behaviour once they were placed in an illuminated environment i.e. whether the horizontally
raised kittens could detect vertically aligned objects and/or if the vertically raised kittens could detect horizontally aligned objects.

Question 2

sample

Answer 2

• Kittens (studied from birth until this report was compiled) were randomly allocated to one of the two conditions.
• Two of the kittens (one reared in a horizontal and one in a vertical environment) were used to study neurophysical effects

Question 3

outline- procedure

Answer 3

The kittens were housed from birth in a completely dark room.
• From the age of two weeks they were put into a special apparatus for an average of about five hours per day.
The kitten stood on a clear glass platform inside a tall cylinder the entire inner surface of which was covered
with high contrast black-and-white stripes, either vertical or horizontal. There were no corners to its
environment, no edges to its floor and the upper and lower limits to its world of stripes were a long way
away. It could not even see its body as it wore a wide black collar that restricted its visual field to a width of
about 130o
(The kittens did not seem upset by the monotony of their surroundings and sat for long
periods inspecting the walls of the tube.)
• This routine was stopped when the kittens were 5 months old (well beyond the ‘critical period’ in which
total visual deprivation causes physiological deficits, Hubel & Weisel, 1970).
• The kittens were then 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 observed and recorded/noted.
• At 7.5 months, two of the kittens (one reared in the horizontal and one reared in the vertical environment) were anaesthetised so their
neurophysiology could be examined.

Question 4

conclusions

Answer 4

Visual experiences in the early life of kittens can modify their brains and have profound perceptual consequences.
• A kitten’s visual cortex may adjust itself during maturation to the nature of its visual experience.
• A kitten’s nervous system adapts to match the probability of occurrence of features of its visual input.
• Brain development is determined by the functional demands made upon it, rather than pre-programmed genetic factors.
• The environment can determine perception at both a behavioural and physiological level – at least in cats. It is questionable as to whether
results can be generalised to humans