Split Brain Research Flashcards
What is hemispheric lateralisation?
The idea that the two hemispheres of the brain perform different functions limited to them specifically.
What is an example of hemispheric lateralisation?
Language as it is localised and hemispherically lateralised to the left hemisphere of the brain.
Who conducted Split Brain Research and why?
Sperry conducted Split Brain Research in order to investigate the extent to which brain functions is lateralised.
Who were the participants in Sperry’s study?
This study involved epileptic patients who had their corpus callosum cut out (this connects the two hemispheres together)
This meant the main communication line between the two hemispheres was removed.
Outline the procedure Sperry used
Sperry presented an image or word to one hemisphere
In the normal brain the corpus callously would immediately share the info between both hemispheres.
However, by presenting the image to one hemisphere of a split brain patient
This meant that the info couldn’t be conveyed from that hemisphere to the other.
What were the findings?
As the corpus callosum was cut, info presented to one hemisphere can only be processed by that hemisphere has no way of sharing info with the other hemisphere.
E.g. An image of a dog was presented to the patients right visual field which will be processed by the left hemisphere. This means the patient was able to state what they see
However when the person is shown something only visible to the left visual field, this will be processed by the right hemisphere which has no language centre.
This means they are unable to express what they are able to see without the aid of language centres in the left hemisphere.
Evaluation: Good Research
Sperry’s work provided a good body of research findings into the split brain
This allowed us to make conclusions that the left hemisphere is more for analytical &a verbal tasks
The right hemisphere is better at performing spatial tasks and music. It produces emotional and holistic content to language.
This work provides us with a key contribution to our understanding of brain processes.
Evaluation: Strengths of the methodology used
The experiment involving split brain patients used highly standardised procedure.
Sperry’s method of presenting visual info to one hemispheric field at a time was seen as ingenious.
This allowed Sperry to vary aspects of the basic procedure and ensured only one hemisphere received info at a time developing a very useful and well controlled procedure.
Evaluation: Issues with generalisation
The study based on split brain patients constitute such an unusual sample of people. Only 11 people took party in this study has a history of epileptic seizures
This is argued to cause unique changes in the brain that may have influenced the findings.
Also some participants has experienced more disconnection of the two hemispheres as part of their surgical procedures than others.
