Sperry’s Split Brain Studies A Key Study of the Biological Perspective
The Study • Hemisphere disconnection and unity in conscious awareness
Syllabus topic • The Brain: Localization of Function
Name of Researcher • Sperry 1968
Method • Case Study
Research Question • How does severing the corpus callosum change mental functioning and conscious awareness?
Our Divided Brain • The information highway from the eyes to the brain
Independent Variable • Objects were presented to either the Right Hand or the Left Hand • Words shown to the Right Visual Field (RVF) or the Left Visual Field (LVF)
Dependent Variables • Participants asked to identify the object or select the object from a group of out of sight objects • Participants asked to identify the word either verbally or by pointing to a word
“What word did you see?” or “Point with your left hand to the word you saw.” “Look at the dot.” Two words separated by red dot appear projected in front of person. Example • a condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them
Participants • Epilepsy patients who had undergone surgery to cut the corpus callosum
Conclusions • The two hemispheres have different abilities and functions • The RH processes information in a synthetic form i.e. seeing the big picture • The LH processes analytically i.e. bit by bit • Participants appeared to have two streams of consciousness • Unlike kidneys and lungs, the two hemispheres are an odd couple
Strengths of the Study • Dramatic demonstration of hemispheric specialization
Right Brain Visual and spatial skills Controls left side of body Receives visual signal from left side only Specialization of Function • Left Brain • Language • Math calculation • Controls right side of body • Receives visual signals from right eye only.
Weaknesses of the study • The Participants had suffered from epilepsy for years • The sample size was small and did not consist of children • Simplistic conclusions about specialization of function
Key Terms • Epilepsy • corpus callosum