Blakemore and Cooper (1970) Flashcards

1
Q

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

A

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

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2
Q

What is the IV?

A

horizontal or vertical environment

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3
Q

What is the DV?

A

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

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4
Q

What is the method?

A

Lab experiment

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5
Q

What are the strengths of a lab experiment?

A
  • high control over EVs allow standardisation = more reliable
  • replicable = more valid and reliable
  • causality can be established
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6
Q

What are the weaknesses of a lab experiment?

A
  • lack ecological validity
  • lack mundane realism
  • artificial
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7
Q

What was the design used?

A

Independent measures

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8
Q

What are the strengths of independent measures?

A
  • reduced chance of demand characteristics and order effects
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9
Q

What are the weaknesses of independent measures?

A
  • individual differences
  • takes more time
  • more participants needed
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10
Q

What is the sample?

A

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

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11
Q

What are the weaknesses of the sample?

A
  • small = lack population validity
  • ungeneralisable to humans due to structural differences
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12
Q

What are the strengths of the sample?

A

lots of detailed qualitative data can be gathered

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13
Q

How long were the kittens studied for?

A

birth - 5 months old

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14
Q

How were the conditions chosen?

A

random allocation

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15
Q

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

A

housed from birth in a completely dark room

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16
Q

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

A

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

17
Q

What was the special apparatus?

A
  • 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
18
Q

What did the kittens wear whilst inside the special apparatus?

A

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

19
Q

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

A

they did not seem upset by the monotony of their surrounding

19
Q

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

A

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

19
Q

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

A

furnished with tables and chairs

19
Q

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

A

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

19
Q

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

A

5 months old

20
Q

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

A

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

20
Q

How old were the 2 kittens in experiment 2?

A

7.5 months

20
Q

What was measured from the 2 kittens in experiment 2?

A

their neurophysiology - listen to the neurons firing

20
Q

What was the purpose of the room in phase 2?

A

so their visuomotor behaviour could be observed and recorded

21
Q

What are 4 controls that were apart of the procedure?

A
  • 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
22
Q

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

A
  • 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)
23
Q

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

A
  • 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
24
Q

What data was collected?

A

qualitative

25
Q

What are the strengths of this type of data?

A

lots of detailed reasoning as to the WHY behind behaviour

26
Q

What are the weaknesses of this type of data?

A

subjective which makes analysis and comparisons across IVs difficult

27
Q

What are the key findings of the neurophysiological examination?

A
  • 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
28
Q

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

A
  • 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