Describe split-brain research

Split-brain research is based on the concept of hemispheric lateralisation, which is the idea that the two hemispheres of the brain have different specialisations, they are not entirely the same. Split brain research originated from Sperry and Gazzaniga (1968). They used participants whose corpus callosum, a bundle of nerve fibres that connects the two hemispheres of the brain, had been severed in an attempt to stop epileptic fits. The meant they were able to send visual information to just one hemisphere at a time, by presenting it to the alternate visual field. They did so by blindfolding one eye and presenting an image to the other eye for a split second. They performed multiple variations of this task. In one variation, when they presented a picture of an object to the participant's right visual field, they could easily describe it, however, when presented to the left visual field they could not describe it, often stating they had not seen anything. Another variation found that when presented simultaneously with two different names of items one either side of their visual field, the participant would say the name of the item in the right visual field, but pick up the item presented to the left. These experiments allowed many conclusions about the differing functions of each hemisphere to be drawn, however, it is important to recognise that this does not show that the brain is organised into discrete regions, but that communication between the hemispheres is vital.