APFCC+-+Sperry

APFCC: Sperry

 * Theorist ** : Sperry
 * Study ** **of**: Hemisphere deconnection and unity in conscious awareness
 * Year ** : 1968

‘Mr Split-Brainy’ - hemispheric speciality. Roles of the different hemispheres - studied through patients who had already had a hemispheric deconnection.
 * Summary: **

The purpose of the study was to investigate localisation of function in the different hemispheres of the brain / show that the different hemispheres of the brain have slightly different functions.
 * Aim: **

He used patients that had an operation to deconnection the hemispheres of the brain to reduce the effects of epilepsy. The patients had their corpus callosum severed to reduce
 * Procedures: **

He found that there was a disconnect between the two hemisphere’s of the brain. Images that were showed to the right view field were sent to the left side of the brain and vice versa. Objects presented in the right visual field (left hemisphere) could be named verbally and in writing. Objects presented in the left visual field (right hemisphere) couldn’t be named in writing or verbally but could be pointed at.
 * Findings: **

The tests imply the one side of the brain does not know what the other side has seen or felt.
 * Conclusions: **

Because this was a natural experiment, as Sperry couldn’t disconnect brain hemispheres, there was a lack of control of variables. Its hard to prove that all of one particular aspect in behaviour can be localised to one hemisphere. The brain is integrated and share functions. The results are also typical of right handed men, left handed people and women might have different localisations.
 * Criticisms: **

The corpus callosums of epileptic patients were severed. Sperry then carried out tests such as showing visual stimuli to one side of the patients’ visual field. || When information was presented to the left visual field, therefore processed by the right hemisphere, the patient could not name them verbally, yet they could identify them by pointing. When the stimulus was presented to the right visual field, therefore processed by the left hemisphere, the patient could name the stimuli verbally but could not point to it.
 * **Aim: ** To determine whether the two hemispheres of the brain have different functions. ||
 * **Procedures: **
 * **Findings: **

A dollar sign was presented to the left visual field and a question mark was presented to the right visual field. The patient was then asked to draw with their left hand what they had seen; they drew the dollar sign that was presented to the left visual field. If the patient was asked what the left hand had drawn, the verbal hemisphere, the left hemisphere, would say what was seen by the right hemisphere (the question mark). || The two hemispheres of the brain appear to have different functions and abilities yet are highly integrated. Without the corpus callosum, the two hemispheres of the brain do not know what the other has processed. ||
 * **Conclusions: **
 * **Criticisms: **
 * The mental abilities of the patients were not tested and so this may have affected the results of the tests.
 * The patients were made up mainly of right-handed men and so these factors may have influenced the results.
 * A strength of the study is that it has implications for helping patients with brain damage. ||