Blakemore and Cooper Flashcards
Key Terms
Brain plasticity
The idea that your brain adapts and changes according to what you do in your life
Background
Hirsch & Spinelli - Kittens were raised with goggles so they could only see vertical stripes in one eye and horizontal stripes in the other. When released into a normal environment, researchers saw the kittens had visual impairments due to the neurons in their visual cortex changing how they were aligned
Key Terms
Visual cortex
The part of the brain that receives and processes sensory nerve impulses from the eyes
Key Terms
Startle response
The ‘backing off’ reaction of a cat when an object is moved quickly towards their face
Key Terms
Visual placing
When a cat puts its feet out to meet the edge of a surface
Aims
To investigate how being raised in a visually restrictive environment would affect the visual brain development of cats
1. Compare the behavioural consequences of raising kittens seeing only horizontal or vertical stripes
2. Investigate the neurophysiological effect on neurons in kittens’ visual cortex
Sample
2 kittens from birth until approxmately 1 year of age
Procedure
- First 2 weeks: Kittens kept in completely dark room
- 2 weeks - 5 months: Kittens put in cylinder with vertical or horizontal stripes for 5hrs every day + wore black collars
- 5 months: Each kitten taken to well lit room with furniture to test behaviour
What was the research method?
Lab experiment
What was the IV?
The orientation of the stripes in the cylinder (horizontal or vertical)
What was the experimental design?
Independent measures - Each kitten exposed to different orientated stripes
What were the controls?
- The same size cylinder
- Same aged Kittens
- The same time spent in the cylinder each day (5 hours)
- Both wearing a black collar
Findings
Initial behavioural results
Though they had normal pupillary reflexes, the cats initially showed visual deficits when taken into the well lit room
* They navigated around the room by touch
* They were generally clumsy
* They had no startle response
* They had no visual placing
Findings
Behavioural results after 10hrs
Recovered:
* Visual placing
* Startle response
Remained:
* Still clumsy in following moving objects
* Still bumped into objects/furniture
Findings
How did the two cats differ?
Blakemore & Cooper described the cats as ‘virtually blind’ to the opposite orientation to their upbringing.
They found this by experimenters shaking a rod in front of the cat and seeing if they responded. They found the cat only responded if the rod was shaken in the same orientation as they had seen in the cylinder.
Findings
Neurophysiological results
Brain scans showed that the neurons in the visual cortex had aligned themselves to match the environment the kitten was brought up in. There were little to no neurons aligned to the opposite direction e.g. the cat brought up within the horizontal cylinder had neurons aligned in a horizontal arrangement
This is because the cats had no need for neurons in the other direction and therefore these were moved elsewhere
What types of data were obtained in the findings?
Behavioural findings - Qualitative data
Neurophysiological findings - Quantitative data
Conclusions
The difference between the kittens suggests that neurons can change their preferred orientation according to the stimulation they receive, matching the ability of the brain to respond to the features in its visual input.
i.e. Neurons change position based on the information they get through our vision and therefore from the environment.
Evaluation
What (animal studies) ethical guidelines could be used to defend or criticise the study?
Defended:
* Replacement - There was no alternative replacement to animals within this research
* Reduction - They reduced the impact to the minimum amount of cats (2)
* Refinement - They refined the procedure by only having the cat in the cylinder for 5 hours a day
Criticised:
Do the benefits outweigh the negatives cause to the animals? - There are not many practical applications of the research and therefore perhaps was not worth harming the kittens for
Evaluation
Ethnocentrism
Not relevant - Study looks at biological factors + the environment the kittens were in was not culturally biased
Evaluation
Reliability
Internal: The procedure was highly standardised and replicable due to the high level of controls (5 hours in the cylinder, wearing the collar)
External: Only 2 kittens were used in this study but perhaps this doesn’t matter as we are investigating biological concepts
Key Terms
Concurrent Validity
When one test provides the same conclusions/results as another test
Evaluation
Validity
- Internal: Seemed to be a good test of brain plasticity as the only difference in the procedure for the kittens was the direction of the stripes
- Concurrent: Provides the same results as Hirsch and Spinelli (we are measuring brain plasticity) + The cats showed the same deficits in 2 separate tests to check their perception of the other orientation
- Population: Possible problem with generalising beyond the species of these kittens
- Ecological: Not a realistic scenario as the environment was so visually restricted. This doesn’t happen in real life
Links to debates
- Nature/Nurture - Nurture as brains can change in response to the visual environment (Brain plasticity).
- Individual/Situational - Behaviour dependent on the situation (Environment) of cylinder orientation
- Usefulness - Not really useful at all as its based on cats not humans!
- Reductionist vs Holistic - The study could be seen as holistic as we are looking at observable behaviour and the brain structure of the kittens (Multiple factors). Could also be reductionist as we only look at the environment the kittens are in (Horizontal or vertical)
