Sperry

AIMS: 

• determine functions of left and right hemisphere
• how that once corpus callosum os severed the hemispheres act independently

METHOD:

• Case Study (11 patients)
• Quasi Experiment with naturally occuring variables - comparrisons between split brain and clincally normal

PARTICIPANTS:

• 11 participants - all had previously suffered from epilepsy which hadn't responded to drugs so had comissurotomy 
• 2 had surgery long time ago, 9 had surgery recently
• OPPORTUNITY SAMPLE - Sperry knew the participants

DESIGN:

• Independent groups (split brain or no split brain)
• Repeated measures (left and right hemisphere)

PROCEDURE:

• pp. had to focus on central point and an image was flashed on screen to one of the fields of vision for 1/10 of a second (other eye covered), the participants had to stay silent unless asked question (if vocalised both HS would know)
• gap below screen so pp. could reach objects with hands but no see what they were doing
• response recorded as right/wrong or time etc... 

RESULTS:

• ONE VISUAL TEST: picture shown to left visual field (RHS) e.g. a Key and the pp. insisted they hadn't seen anything but when the key was shown to the right visual field (LHS) the pp. was able to name/talk about the object. RHS IS APHASIC (no language)
• DOLLAR/QUESTION MARK: $ (left visual field) and ? (right visual field) presented simultaneously for 1/10 of a second, asked to draw what they'd seen - they drew a dollar sign, but said they'd drawn a question mark. ONLY SOURCE OF LANGUAGE IS LHS, HEMISPHERES ACT INDEPENDENTLY
• FINDING OBJECTS: present picture/object to…