Split Brain Research Flashcards
What are split brain patients?
Those who have had their connections between the right and left hemisphere (corpus callosum) severed. Normally the two hemispheres share information. When eyes visual fields are restricted, the differences between the left and right hemisphere functioning can be seen.
What processes are involved in split brain research?
It uses a split visual field experiment. Pts are sat in front of a screen and asked to gaze at a fixed point in the centre of the screen. Visual stimuli are projected onto a screen either to the right or left visual field at a very high speed so the pt has no choice but to move their head and is only able to process the image in the visual field where it is placed.
What was found from the verbal responses to language in split brain research?
Words were projected to the LVF, so going to the right hemisphere. The words did not seem to be registered, which suggests that the left hemisphere is responsible for language.
What was found from the physical responses to language in split brain research?
A word was presented to the LVF so goes to the right hemisphere. The left hand was placed behind a screen and then had to select the object from a number of items. Pts could select the correct object despite being unable to verbally report having seen it. This indicates that the right hemisphere does have the same language ability for understanding words if bot for speech.
What was found from the matching abilities in split brain research?
A different face was presented to each hemisphere at the same time. Pts were then given a set of faces to look at and asked to select those they had seen earlier. Pts chose the one presented to the right hemisphere indicating its role and identifying faces and shapes. This indicates that the right hemisphere is responsible for visuospatial tasks.
Does split brain research have practical applications?
Enables a greater understanding of different functions in hemispheres. We now know that language is largely processed in the left hemisphere so we can now target this area for therapy when there are problems of aphasia.
Does the split brain research lack generalisability?
Limited number of participants - 11 went through all tasks. Pts varied in age, gender and handedness as well as the age at which they developed epilepsy, plus the degree of drug therapy they have experienced before the operation.
Can we establish cause and effect with split brain research?
It could be that epilepsy causes changes in the brain that influences the findings. Some pts experienced more disconnection of the two hemispheres.
Does split brain have methodological strength?
Experiments were highly specialised used standardised procedures. Presenting visual info to one hemisphere at a time could be controlled so could easily vary aspects whilst still maintaining control.
Is there research to contradict the findings of split brain research?
Kim Peek was born without a corpus callosum but she could read out loud from a book from the right and left pages at the same time. If language was lateralised to the left hemisphere she would only be able to read words from the right page.
Who did split brain research?
Sperry
