Blakemore and Cooper (1970)

Question 1

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

Answer 1

to investigate the development of the primary visual cortex (in cats) and to find out if orientation selectivity are innate or learned (plasticity)

Question 2

What is the IV?

Answer 2

horizontal or vertical environment

Question 3

What is the DV?

Answer 3

visuomotor behaviour:
- startle response
- visual placing
- object detection
- neurophysical behaviour

Question 4

What is the method?

Answer 4

Lab experiment

Question 5

What are the strengths of a lab experiment?

Answer 5

• high control over EVs allow standardisation = more reliable
• replicable = more valid and reliable
• causality can be established

Question 6

What are the weaknesses of a lab experiment?

Answer 6

• lack ecological validity
• lack mundane realism
• artificial

Question 7

What was the design used?

Answer 7

Independent measures

Question 8

What are the strengths of independent measures?

Answer 8

• reduced chance of demand characteristics and order effects

Question 9

What are the weaknesses of independent measures?

Answer 9

• individual differences
• takes more time
• more participants needed

Question 10

What is the sample?

Answer 10

not stated as to how many cats EXCEPT in part 2: x2 kittens used to study neurophysical effect

Question 11

What are the weaknesses of the sample?

Answer 11

• small = lack population validity
• ungeneralisable to humans due to structural differences

Question 12

What are the strengths of the sample?

Answer 12

lots of detailed qualitative data can be gathered

Question 13

How long were the kittens studied for?

Answer 13

birth - 5 months old

Question 14

How were the conditions chosen?

Answer 14

random allocation

Question 15

How did the kittens live for the first two weeks of their life?

Answer 15

housed from birth in a completely dark room

Question 16

How did the life of the kittens change at two weeks old?

Answer 16

they were put into a special apparatus for an average of 5 hours per day

Question 17

What was the special apparatus?

Answer 17

• tall cylinder
• clear glass platform (where the kitten stood)
• entire inner surface was covered in high contrast black and white stripes (vertical or horizontal)
• no corners or edges

Question 18

What did the kittens wear whilst inside the special apparatus?

Answer 18

a wide black collar so their visual field was restricted to 130 degrees (could not see body)

Question 19

What is important to note about the kittens reaction to the special apparatus?

Answer 19

they did not seem upset by the monotony of their surrounding

Question 19

Why were the kittens stopped at 5 months old from going into the apparatus?

Answer 19

it was considered past the ‘critical’ period and physiological deficits could have affected observations due to visual deprivation

Question 19

What was inside the room that the kittens were placed into during phase 2?

Answer 19

furnished with tables and chairs

Question 19

What had previous research recommended in regards to the development of kittens’ vision?

Answer 19

suggests there is a ‘critical’ period in the development of the visual cortex and if changes occur past the period they are likely to cause irreversible deficits in vision

Question 19

When was the routine of going into the special apparatus stopped?

Answer 19

5 months old

Question 20

What did the kittens do after they stopped going into the special apparatus?

Answer 20

they were taken for several hours each week from their dark cage into a small, well-lit room

Question 20

How old were the 2 kittens in experiment 2?

Answer 20

7.5 months

Question 20

What was measured from the 2 kittens in experiment 2?

Answer 20

their neurophysiology - listen to the neurons firing

Question 20

What was the purpose of the room in phase 2?

Answer 20

so their visuomotor behaviour could be observed and recorded

Question 21

What are 4 controls that were apart of the procedure?

Answer 21

- black collar to restrict vision of anything except IV (stripes) - same age when going into the cylinder (2 weeks) - same timings - in cylinder for 5 hours a day - stopped going in cylinder at 5 months old

Question 22

What were the key findings as an effect of the special apparatus?

Answer 22

- regardless of IV kittens were initially extremely visually impaired - showed behavioural blindness: 1) showed no visual placing (not putting paws on the table when about to be put down) 2) guided themselves mainly by touch 3) showed no startle response - in vertical IV they could not detect a rod held horizontally in front of them (unless it made a noise)

Question 23

What are the key findings after time spent in the room?

Answer 23

- after 10 hours of normal vision they began to show startle response and visual placing - some deficits were permanent: always followed moving objects with jerky head movements

Question 24

What data was collected?

Answer 24

qualitative

Question 25

What are the strengths of this type of data?

Answer 25

lots of detailed reasoning as to the WHY behind behaviour

Question 26

What are the weaknesses of this type of data?

Answer 26

subjective which makes analysis and comparisons across IVs difficult

Question 27

What are the key findings of the neurophysiological examination?

Answer 27

- showed no evidence of severe astigmatism - kittens showed physical blindness - distinct orientation selectivity - 75% of cells in both cats were binocular - no obvious large regions of 'silent cortex' = suggests that neurons had been respecialised

Question 28

What are the conclusions that can be drawn from this study?

Answer 28

- visual experiences in the early life of kittens can modify their brains - a kittens visual cortex may adjust itself during maturation - brain development is determined by functional demands made upon it rather than preprogramed genetic factors - the environment determines perception