Split brain research

Question 1

what is split brain research?

Answer 1

A
Research that studies individuals who have been subjected to the surgical separation of the two hemispheres of the brain as a result of severing the corpus callosum

Question 2

Explain Sperry and Gazzaniga’s research

Answer 2

• To test the capabilities of the separated hemispheres, they were able to send visual information to just one hemisphere at a time in order to study hemispheric lateralization
• Patients were presented with images that would be projected to the left and right hemisphere many different experiments were used such as describe what you see task,tactile task and drawing tasks of which patients had to respond to with either their left or right hand

Question 3

Who were the first researchers to investigate split brain research?

Answer 3

Sperry and Gazzaniga

Question 4

Explain the findings of their research

Answer 4

• The results of this found that patients could say what they saw in their right visual field but not in their left hemisphere as the left hemisphere is responsible for language and the right is not
• However, patients could draw this image with their left hand as the task did not require language
• From this sperry concluded that the left hemisphere is responsible for speech and language while the right hemisphere specialises for visual/spatial motor tasks

Question 5

How do split brain patients process visual tasks?

Answer 5

• Information passed through the left visual field goes to the right hemisphere
• information passed to the right visual field goes to the left hemisphere
• there is nothing to connect the two hemispheres

Question 6

Name a first evaluation point

Answer 6

Language may not be restricted to the left hemisphere. Gazzianiga in 1998 suggests that some of the early discoveries from split-brain research have been disconfirmed by more recent discoveries.
- Damage to the left hemisphere was found to be far more detrimental to language function than damage to the right however case studies demonstrate that this was not the case. J.W developed the capacity to speak out of the right hemisphere with the result that he can now speak about information presented to the left and right brain. (Turk et al 2012)
Limitations of split brain research

Question 7

Name a second evaluation point

Answer 7

Andrews in 2001 pointed out that studies are presented with as few as three participants or just one single participant. Conclusions are drawn from individuals who have a confounding physical disorder that made the split-brain procedure necessary or who has a less complete sectioning of the two hemispheres than was originally believed. Therefore patients who have had this procedure without confounding factors are rarely encountered in sufficient numbers to be useful for this research

Question 8

Name a final evaluation point

Answer 8

A strength of split brain research is that they are done using highly specialised and standardised procedures. For example, Sperry investigated one hemispheric field by presenting visual information to one hemispheric field at a time
An image would be flashed 1/10th of a second so patients wouldn’t have time to move their eye across the image and so spread information to both sides of the visual field this ensured that information was presented to one hemisphere. Therefore he developed a well performed procedure as this could be replicated to check for reliability