What are the two studies in the biological area
Blakemore and Cooper
Maguire
What is brain plasticity
The brain can change and modify due to environment and experiences (e.g. volume increase/decrease)
What is the key theme in the Blakemore and Cooper study
Brain plasticity and development / Impact of early visual experience
What is the aim of the Blakemore and Cooper study
To investigate the development of the primary visual cortex (in cats) and to find out if some of its properties such as orientation selectivity are innate or learned
Research method in the Blakemore and Cooper study
Laboratory experiment
IV of the Blakemore and Cooper study
-Whether the kittens were reared in a horizontal or vertical environment
DV of the Blakemore and Cooper study
-Visuomotor behaviour once they were placed in an illuminated environment i.e. whether the horizontally raised kittens could detect vertically aligned objects and/or if the vertically raised kittens could detect horizontally aligned objects
Sample Blakemore and Cooper study
New born kittens
Briefly describe the procedure of the Blakemore and Cooper study
- The kittens were put into special apparatus in a tall cylinder with either vertical or horizontal lines for 5 hours per day
- This routine stopped when the kittens were 5 months
- Visual reactions were then observed in a well-lit furnished room
Main Results from Blakemore and Cooper study
- Their papillary reflexes were normal but they showed no visual placing when brought up to a table top and no startle response when an object was thrust towards them
- They guided themselves mainly by touch
- They were frightened when they reached the edge of a surface they were standing on
Conclusion from the Blakemore and Cooper study
- Visual experiences in the early life of kittens can modify their brains and have profound perceptual consequences
- A kittens’ visual cortex may adjust itself during maturation to the nature of its visual experience
Reliability - Blakemore and Cooper
-Standardised and same procedure for each kitten making it more reliable because, it would be easily replicated and could gain the same or similar results
What is the aim of the Maguire study
-To show that the hippocampus in the human brain is the structure associated with spacial memory and navigation
Research method in the Maguire study
Quasi/Natural experiment
IV in the Maguire study
-Whether the participant was a London taxi driver or a person who did not drive taxis
DV in the Maguire study
-The volume of the hippocampi including their anterior, body and posterior regions; measured by analysing MRI scans of participants’ brain using the two techniques of VBM and pixel counting
Sample in the Maguire study
- 16 right-handed, male, London taxi drivers that had been driving taxis for more than 11.5 years
- 50 brain scans of healthy right-handed men who were not taxi drivers
Briefly describe the Procedure in the Maguire study
-The scans of the control group were selected from the structural MRI scan data base at the same unit where the taxi drivers were scanned
Main results from the Maguire study
- Taxi drivers had significantly increased grey matter volume in the right and left posterior hippocampi compared to controls
- Taxi drivers had a significantly greater posterior hippocampi volume than controls
Conclusions from the Maguire study
- There are regionally specific structural differences between hippocampi of licenced London taxi drivers compared to those who do not drive London taxis
- The professional dependence on navigational skills in licensed London taxi drivers is associated with a relative redistribution of grey matter in the hippocampus
Reliability - Maguire
-Standardised population and procedure of MRI scan, can easily be replicated because they were just scanning the brains of the taxi drivers compared to the non-taxi drivers. However, a specialist, competent individual will need to carry out the pixel counting.
Internal Validity - Blakemore and Cooper
-As this was a laboratory experiment, the kittens’ environments were highly controlled by immediately putting the new born kittens into a dark room
External validity - Blakemore and Cooper
- The population was very small and therefore can not be representative, also can not be generalised to human because they are a different species with very different biological processes
- In the real world, this situation would not happen
Internal validity - Maguire
- The same competent specialist individual was used during the pixel counting stage
- All the taxi drivers were right handed and had been driving for more than 1.5 years
