Sperry (1968) Split Brain

• Regions - different areas of the brain have specialised functions - localisation of functions
• Left and right hemispheres have different specialities - lateralisation
• Aim - to investigate effects of hemisphere splitting and to show how each hemisphere functions differently
• Background - surgeons noticed that if hemispheres were seperated seizures were contained in one half of the brain causing less damage. Cutting the corpus callosum in two greatly reduced epilepsy symptoms
• Procedure - 11 male and female 'split-brain' patients due to life threatening epilepsy
• Procedure - vision tested using an upright screen, slides and a projector fitted with a shutter

  One eye covered and visual stimuli sent to just one hemisphere by fixating on a point in the middle of the screen where an image is projected for less that 1/10 of a second to stop eye movements changing visual fields

  Space to place hands so they can write, draw or feel object out of sight of vision

  Results were compared to normal non split-brain patients
• Quantitative results - the answers to the test e.g. how many felt an object in their right hand, or didn't report seeing an image projected to LVF (right hemisphere) and comparison with the normal control group
• Qualitative results - language is based in the left hemisphere so split-brained patients shouldn't name anything presented to only the right hemisphere or be able to draw/point with left hand anything sent to just the left hemisphere
• Most of the time it appears that the major left hemisphere is in control
• Conclusion - sperry argued studies give considerable support to theory of laterilisation of function. Different areas of the brain specialise on different tasks e.g. left hemisphere responsible for language and right hemisphere spatial ability