Blakemore and Cooper (classic study)

Question 1

What is neuroplasticity?

Answer 1

The idea the brain can undergo functional/structural changes such as changes in neurones orientation or size in response to an external stimuli

Question 2

What was the name of background research to this study?

Answer 2

Hirsch and Spinelli

Question 3

Hirsch and Spinelli research outline

Answer 3

Used a kitten wearing goggles: one eye exposed to vertical stripes/one eye exposed to horizontal stripes

Question 4

Hirsch and Spinelli findings

Answer 4

Neurones in the visual cortex preferred orientation of the stripes the eye saw: seeing horizontal stripes meant the neurones had changed direction to reflect this thus mainly saw horizontal contours

Question 5

2 aims of this study

Answer 5

Compare behavioural differences in 2 kittens raised in a horizontal striped environment from birth to a vertical striped environment

Question 6

2 aims of this study

Answer 6

Compare behavioural differences between 2 kittens raised in a horizontal striped environment from birth to a vertical striped environment
Investigate neurophysiological effect on neurones in the kittens visual cortex due to raising them in different environments

Question 7

What type of experiment is this?

Answer 7

Lab experiment, had an independent variable manipulated by the researcher and controls

Question 8

Independent variable

Answer 8

The orientation of stripes in the environment each kitten was raised in, either horizontal or vertical

Question 9

List of controls

Answer 9

Time spent in the cylinder
Same width of cylinder
Both kept in a dark room when not in a cylinder: not exposed to any other light
Kittens used from birth (same method of raising the kittens)

Question 10

Experimental design

Answer 10

Independent measures

Question 11

Why was this study independent measures?

Answer 11

Because each kitten only went through one condition of being raised in either the horizontal or vertical striped cylinder and were not then repeating the experiment in the other condition

Question 12

2 dependent variables

Answer 12

The behaviour of kittens once put into a normal environment (qualitative)
The orientation of the neurones of kittens in the visual cortex (quantitative)

Question 13

How were the kittens raised in the first 2 weeks of their life?

Answer 13

In a completely dark room with no exposure to light: no external effect on the orientation of neurones in the visual cortex

Question 14

General procedure

Answer 14

Depending on horizontal/vertical striped condition, kitten was put in the cylinder for 5 hours every day for 5 months
So only light exposed to was different striped orientations
And spent the rest in complete darkness

Question 15

What was the cylinder like?

Answer 15

Same height and radius for both kittens
Illuminated stripes depending on condition
Glass platform to reflect stripes below them
Lid on top so could only see stripes

Question 16

What were the kittens wearing in the cylinder?

Answer 16

A black collar to limit vision of their body to only see stripes

Question 17

After the 5 months, what did the researchers do to observe behaviour of kittens?

Answer 17

Put in a well lit room with furniture (standardised for both kittens) to see how they behave

Question 18

How many kittens were used in this study?

Answer 18

2
1 in each condition (saw either striped or vertical illuminates stripes in the cylinder)

Question 19

2 Observations of when the kittens were put in their own room that disappeared after 10 hours

Answer 19

Had no startle response when an object was thrust toward their face
Did not show visual placing

Question 20

What visual deficits did not disappear from the cats?

Answer 20

Virtually blind to contours perpendicular to the orientation of lines they experienced in the cylinder

Question 21

What visual tests were done to test kittens visual deficits to seeing contours?

Answer 21

Shaking a rod in various directions
Presented a sheet of black and white lines in different orientations

Question 22

Results for presenting a sheet of black and white lines to kittens

Answer 22

If the lines were horizontal shown to kitten in vertical cylinder, they had no reaction (blind to it)
If the lines were vertical shown to kitten in horizontal cylinder, they had no reaction (blind to it)
But would react if the lines were in same orientation to which they were raised

Question 23

Investigating the actual orientation of visual neurones

Answer 23

By completing procedures to investigate the angle at which visual neurones preferred contours (thus could actually see) in these 2 kittens compared to a normal kitten: involved inserting electrodes

Question 24

Visual neurones in a vertical striped raised kitten

Answer 24

No visual neurones preferred the horizontal orientation: explains why they could only see vertical contours

Question 25

Visual neurones in a horizontal striped raised kitten

Answer 25

No visual neurones preferred the vertical orientation: explains why they could only see horizontal contours

Question 26

Conclusions of the study

Answer 26

Visual stimuli can have consequences on the structural development of the brain:
Kitten raised in vertical striped environment only had neurones that preferred vertical orientations thus could only see them
Which effects behaviour (observations)
Evidence for brain plasticity

Question 27

3 animal rights ethics

Answer 27

Replacement
Reduction
Refinement

Question 28

Replacement ethics

Answer 28

If animals can only be used because it would be too unethical to experiment on humans

Question 29

Reduction ethics

Answer 29

Keep the number of animals experimented on at a minimum

Question 30

Refinement ethics

Answer 30

The severity of any procedures is limited

Question 31

Evaluate the replacement ethics in this study

Answer 31

This study that investigates how the brain’s structure changes from birth would be way too unethical to complete on human babies

Question 32

Evaluate reduction ethics in this study

Answer 32

The minimum number of 1 kitten per condition (2 kittens) were used

Question 33

Evaluate the refinement ethic in regard to this study

Answer 33

The kittens were only trapped for 5 hours and not the whole day
Observing neurones did not kill the kitten and they were anaesthetised (little pain)

Question 34

Criticise animal ethics of this study

Answer 34

The findings have little benefit to humans (limited practical applications) so may not outweigh the long term visual deficits these kittens were given
This is also because findings may not apply to humans (?)