day 2 : biopsychology

Question 1

What is hemispheric lateralisation?

Answer 1

two halves of the brain are functionally different and that certain mental processes and behaviours are controlled by one hemisphere rather than other.

Question 2

split brain research
- who carried out this research?

• why did he carry out this research?
• what was the aim?
• what was the method?
• what was the key findings?

Answer 2

Sperry (1968)
- split brain patients are unique group of indivuals who had undergone same surgical procedure- in which there corpus callosum and other tissues which connected were cut down in the middle to separate two hemispheres to control frequent and severe epilepsy.

aim : examine the extent to which two hemispheres are specialised for certain functions.

method : an image or word can be projected to indivuals right visual field ( processed by left hemisphere) or left visual field ( processed by right hemisphere)
- in normal brain the corpus callosum would immediately share info between two hemisphere. however split brain indivuals meant the information could not be sent from one hemisphere to another.

key findings
1. describing what you see: when a picture of object was shown to indivual right visual they could easily describe what was seen. however when it was shown to left visual they could not describe what is seen. this is because of lack of language centres in right hemisphere.

2. recognition by touch = when patients were presented with word or object in left visual field then had to select a object from the bag using their left hand without looking they were able to do quite well. shows right hemisphere is involved in understanding objects.
3. composite words : when patients were presented with 2 words simultaneously. the left hand was better at drawing images than the right hand.
4. matching faces : when asked to match a face from number of other faces the right hemisphere was consistently selected whilst left hemisphere was ignored. shows right hemisphere seems dominant in face regonition.

Question 3

evaluation

Answer 3

1. Sperry research supports that the left hemisphere is more responsible for verbal and analytic task and right hemisphere is better at spatial and musical task. this has strengthened the understanding of how the brain works
2. Sperry research was closely controlled. patients were given eye patches and images were flashed up for a very brief time. meaning there was no possible looking over and using other visual field. these strengths the internal validity of studies.
3. sample used by Sperry was small and their brains may have been affected by epileptic seizures. therefore, it harder to generalise the findings of these studies to general population.