Sperry Flashcards
Aim
To study the psychological effects of hemisphere disconnection in split-brain patients and to use the results to understand how the right and left hemispheres work in ‘normal’ individuals.
Sample
11 patients that underwent hemisphere disconnection of the brain because of severe epileptic seizures.
Background
Sperry’s previous study on the connection between brain structure and experience.
Research questions
What happens when the two halves of the brain are disconnected?
Do the hemispheres perform different functions?
Does each hemisphere have its own memories, perceptions and concepts?
Procedure
Ppt was set up at a station.
The station consisted of a visual screen and a desk with a gap wide enough to reach through but out of the ppt’s sight.
The ppt covered one eye and was asked to look into the projection screen at a fixed point. Pictures were then shown to that visual field at 0.1 of a second or faster. They were asked to say what they see and then this was repeated for the other eye.
The second task was tactile. Ppts were asked to feel the objects with one hand and without looking and name what they feel. They then repeated this for the other hand.
Results
Pictures shown to the left visual field were not recognised when then shown to the right visual field.
Pictures shown to the right visual field could be described in speech and writing.
Pictures shown to the left visual field could be identified with their left hand but not their right.
Example key is shown to LVF and case to RVF.
Left hand picks up key.
Right hand spelt out case.
Conclusions
When hemispheres are disconnected one half becomes unaware of what the other half is doing.
The left hemisphere specialises in speech and writing (language). The right side of the body is connected to the left hemisphere.
The right hemisphere is mute and does hold the capacity for language. The left side of the body is connected to the right hemisphere.
IV
Naturally occurring.
Patients with hemisphere disconnection in the brain.
DV
Brain functions and ability on tasks.
Method
Lab experiment. Snapshot study
Evaluations/changes
Procedure - longitudinal study instead
Sample - look at other brain surgery effects on people and brain function
More people