Sperry

• Procedure:

  • Compared split brain patients to others with no hemisphere separation.
  • Different activities where tried witht he patients including touch of objects and visual presentation of stimuli to see how the different sides perform on tasks.


  Key study - Sperry (1968)
• Visual tasks

  • A word or picture is projected into the left or right visual field and patient will be asked something about that stimuli.

  Tactile tasks

  • Were carried out with ppts hands underneath a screen so the ppts could not see what they were touching.
  • The had to use ‘feel’ only.

  Key study - Sperry (1968)
• Independant variable - Cut corpus callosum or uncut corpus callosum.


  Key study - Sperry (1968)
• Dependant variable - how the ppt behaved.


  Key study - Sperry (1968)
• Findings:

  • Left visual field, left hand.
  • They could select the object because it was seen by the right hemisphere.
  • They could not speak about the object.


  Key study - Sperry (1968)
• Findings - recognition by touch:

  • Left visual field, right hand.
  • If the left hand picked up the right hands object, it would be rejected.


  Key study - Sperry (1968)
• Conclusions:

  • Hemispheres of the brain process information separately.
  • Hemispheres do have different functions supporting lateralisation.
  • Two separate streams of consciousness with their own memories and perceptions.


  Key study - Sperry (1968)
• Findings - Composite words:

  • If two words were presented simultaneously, one on either side of the visual field.
  • The patient would say one word but write the other with their left hand.
  • This is because the left hand is controlled by the right hemisphere, collecting information from the left visual field.


  Key study - Sperry (1968)