Blakemore and Cooper's Study

Question 1

What is comparative psychology?

Answer 1

When we use animal research to find out something about humans

Question 2

Define the term ‘brain plasticity’?

Answer 2

Brain plasticity is the idea that your brain adapts and changes (rewires itself) according to what you do in your life.

Question 3

What is a ‘visual cortex’ (visual neurone’s)?

Answer 3

They are nerve cells controlling vision in the brain

Question 4

What is a ‘startle response’?

Answer 4

This is where a reaction or movement occurs when a defect is thrust towards a person or animals face

Question 5

What is ‘visual placing’?

Answer 5

The ability to use spatial awareness to place arm/lrg/foot on a flat object (eg. a table)

Question 6

What is the background to Blakemore and Cooper’s study?
Refer to the other researchers

Answer 6

Hirsch and Spinelli worked at Stanford University.
They found they could change the way the neurons in the visual cortex aligned themselves by controlling what kittens could see as they grew up.

Kittens were raised could only see vertical stripes in on eye and horizontal stripes in the other eye.

When the cats were then released into an everyday environment, the researchers found that they had visual impairments.

Blakemore and Cooper wanted to build on this research

Question 7

What was the overall aim of the study?

Answer 7

To investigate how being raised in a visually restrictive environment would effect the visual brain development of cats;
1. Compare t he behavioural consequences of raising kittens seeing horizontal/vertical stripes
2. Investigate the neurophysiological affect on nuerones in kittens visual cortex

Question 8

Describe the sample used in Blakemore and Cooper’s study?

Answer 8

2 new born kittens who were raised in complete darkness in the lab

Question 9

Describe the procedure of the study?

Answer 9

At two weeks old the new born kittens (who had been raised in complete darkness) were placed inside the cylinder
The kitten was placed on a glass platform inside the cylinder which had vertical/horizontal high contrast black and white stripes which varied in width. The stripes were illuminated by a spotlight beneath the lid of the cylinder
The kittens wore a large black collar so that they couldn’t see the rest of their bodies
They spent 5 hours per day in this apparatus for 5 months
After 5 months (after the critical period of development was over) they were put in well lit room with furniture (including tables and chairs). Their behaviour was observed here.

Question 10

Describe the apparatus utilised in the experiment?

Answer 10

The kitten was placed on a glass platform inside the cylinder which had vertical/horizontal high contrast black and white stripes which varied in width. The stripes were illuminated by a spotlight beneath the lid of the cylinder

Question 11

Describe the time frame of events?

Answer 11

Up to 2 weeks - raised in complete darkness
2 weeks - 5 months spent 5 hours per day in the cylinder

Question 12

What was the independent variable of the study?

Answer 12

Whether the kitten were raised in a horizontal/vertical line environment

Question 13

What was the dependent variable of Blakemore and Cooper’s study?

Answer 13

Whether kittens raised in a horizontal line environment could detect vertically aligned objects and vice versa

Question 14

What experimental design was used in Blakemore and Cooper’s study?

Answer 14

Independent Measures Design

Question 15

What controls were employed in this study?

Answer 15

• Same hours in cylinder
• Same time in new environment
• Same treatment/collar

Question 16

What were the initial behavioural findings and visual defects kittens showed when first placed in a well lit room?

Answer 16

No startle reflex
No visual placing - They were frightened when they reached the edge of the surface they were standing on
Showed behavioural blindness in that the kittens raised in the horizontal environment could not detect vertically aligned objects and vice versa.

Question 17

After 10 hours of exposure to the well lit surroundings what changed and what deficits did the kittens still show?

Answer 17

Deficits which they cats quickly recovered from included;
- Showed a startle response
- Visual Placing
- Could jump which ease from chair to floor

Deficits which remained;
- They always followed moving objects with very clumsy, jerky head movements.
-They often tried to touch things moving on the other side of the room, well beyond their reach i.e. poor spatial awareness

Question 18

How did the Vertically / horizontally raised cats differ?

Answer 18

Vertical cat = struggled to see horizontal objects in the room

Horizontal cat = difficulty in seeing vertical objects

Question 19

Describe the procedure for the neurophysiological tests?

Answer 19

To conduct this part of the experiment, the two cats (aged 7.5 months) were anaesthetised (with nitrous oxide) and then paralysed (with succinylcholine), and their eyes opened.
Electrodes were then inserted into the primary visual cortex to take electrical readings from individual neurons.
The visual neuron activity was recorded to show the optimal orientation for each neuron when shown bright slits or edges of light. Recordings were taken from 125 neurons in total: 52 from the horizontally reared cat, and 72 from the vertically reared cat; there was one which had a concentric receptive field (a circle) so this was discounted.

Question 20

When raised in normal surroundings how do neurone’s align themselves?

Answer 20

When you are raised in normal surroundings neurons align themselves so that you can see objects at different angles.

Question 21

What were the major findings from the neurophysiological test?

Answer 21

The neurophysiological examination found no evidence of astigmatism (blurred vision), but there was evidence that horizontal plane recognition cells did not ‘fire-off’ in the kitten from the vertical environment and vice-versa – meaning that kittens were unable to see things normally (perform orientation selectivity) and therefore they suffered from ‘visual blindness’. Blind spots

Question 22

What two conclusions were drawn from Blakemore and Cooper’s study?

Answer 22

1. Visual neurons can change their preferred orientation
   according to the stimulation they receive, (restricted
   environment in cylinders)
2. After initial visual environmental restriction cats brains re-wired themselves - brain plasticity !!

Question 23

What are the 3 dimensions to weigh up the costs and benefits of using animals in research?

Answer 23

• The degree of animal suffering: ethical research minimises this
• The benefits of the findings: ethical research will have clear benefits
• The quality of the research: ethical research will be highly valid and reliable

Question 24

How can Blakemore and Coopers study be defended in relation to ethics?

Answer 24

REPLACEMENT
Replacing animals with non-sentient alternatives whenever possible

REDUCTION
Reducing the number of animals used

REFINEMENT
Refining procedures to minimise suffering

Question 25

How can Blakemore and Coopers study be criticised in relation to ethics?

Answer 25

Generalisability issues - inferring results from animals to humans..
Ethics = Harm
Not “species specific behaviour”

Question 26

What is an advantage of using animals in research?

Answer 26

Easier to control than human participants
Less likely to change their behaviour and show demand characteristics
Can be used if it would be unethical to carry the study out using humans
Debate – usefulness

Question 27

Why is it not appropriate to discuss ethnocentrism in relation to this study?

Answer 27

It is part of comparative psychology and studied cats so is not relevant to the discussion of cultural bias

Question 28

Evaluate the internal reliability of Blakemore and Coopers study?

Answer 28

It was a highly standardised procedure undertaken in a lab environment – So it would be easy to replicate.

Question 29

Evaluate the external reliability of Blakemore and Coopers study?

Answer 29

it had a very small sample size – 2 kittens to small a sample to establish whether they results weren’t a ‘fluke’

Although shows consistent effect as results proven vice versa

Question 30

Evaluate the internal validity of Blakemore and Coopers study?

Answer 30

As there was a high level of control (laboratory setting) there would have been few extraneous variables, so the researchers could be fairly certain that the environment the kittens were in caused the findings

Question 31

Evaluate the population validity of Blakemore and Coopers study?

Answer 31

Not all different breed/ages of cats are used so may not be applicable to all cats let alone humans who have a different physiological make up

Question 32

Evaluate the concurrent validity of Blakemore and Coopers study?

Answer 32

It helps prove kittens brains are influenced by their environment
- Supported Hirsch and Spinelli’s research
- There were behavioural and neurophysiological findings that supported the results

Question 33

Evaluate the ecological validity of Blakemore and Coopers study?

Answer 33

It is a realistic environment for lab cats (learnt experience)

Question 34

What is a practical application of Blakemore and Cooper’s findings?

Answer 34

This study is important in understanding the effects of visual deprivation in growing children.

If visual impairments are not picked up & corrected early then it is possible that some long term damage might be done to the cortical area of the brain associated with types of stimuli that cannot be seen

E.g. a child with a squint cannot make both eyes point in the same direction – if this is not corrected it could result in a decline in the number of binocular cells.