Split-brain Research Flashcards
What was the basis of split-brain research?
11 participants with a severed corpus callosum to treat epilepsy. Left visual field = right hemisphere etc. Information had no way of travelling so is processed in the hemisphere it’s received.
What was the split brain research procedure?
11 participants fixated on a dot in the centre of the screen while information was present to either the left or right visual field. They then had to make responses with their left hand (right hemisphere) or right hand (left hemi sphere). There were 3 conditions : describe what you saw, recognise what you could see by touch and write/say what they had seen.
What were the findings from the describing what they could see condition?
When it was presented to the right visual field, they could describe it because it was processed in the left, containing language centres. If it was in the left visual field, they said nothing was there.
What were the findings from the recognising objects by touch condition?
If info was presented to the left visual field, they could choose the correct matching object and also pick up an object similar to the image with their left hand (right hemisphere = spatial info). However they couldn’t name it. If it was to the right visual field, with their right hand, they couldn’t pick it up or choose an object.
What happened in the asking participants to process composite words condition?
They could pick up the word on the left and write the word with their left hand but couldn’t say it. They could say the word on the right but couldn’t pick anything up to do with it
What did the research show?
Left = language, right = spatial info. Significant differences in hemispheric localisation but doesn’t show how the brain is organised into discrete regions. Suggests the connectivity is as important as the operation of different parts.
Evaluate the split - brain research (SSSSCCCCI)
S - influential in helping prompt debate and incited a paradigm shift
S - meaningful stimuli to everyday life
S - highly controlled
S - plausible experiment set up and stimulus means high validity
C - methodological - case study
C - brain plasticity
C - pps not matched on level of hemispheric separation / drug therapies
C - brain damaged people
I - methodological - 11 participants = small sample
How was the study highly controlled?
Standardised procedures, fixation point ensured they were looking at the centre of the screen so control what hemisphere info went in to, fast presentation of stimuli (1/10th of a second) meant they didn’t have time to move their eye, participants matched on age and gender
