Split brain research

• Brain


  • Left hemisphere
  • Right hemisphere
• Cutting connection between left and right hemispheres

  Could affect ability to cope or even notice
• Contralateral


  Left side of brain senses and moves right side of body, right side of brain senses and moves left side of body
• Visual information processing


  Right hemisphere deals with left visual field, left hemisphere deals with right visual field
• Language centres


  Located only in left side of brain
• Corpus callosum


  Thick bundle of nerve fibres allowing communication between hemispheres
• Cutting corpus callosum


  1. Stops communication between hemispheres

  2. Demonstrates hemisphere specialisation
• Cutting corpus callosum was a surgical procedure for treating severe epilepsy
• Patients reported few side effects aside from strange sense of being two people in one body
• Split-brain research


  Studies by Sperry in 1969 on people who had corpus callosum cut
• Divided field experiment


  1. Words/images flashed to right or left visual field

  2. Participant could only respond with information in left hemisphere language centres
• Patients could not speak words shown to right hemisphere
• Right hemisphere could draw objects shown to it
• Right hemisphere better at recognizing faces shown to it
• Research suggests we are not one unified self, but a collection of separate intelligent processes
• Alien hand syndrome


  One hand seems to fight the rest of the body and act under separate control
• Alien hand syndrome


  • Patient's alien hand attempted to address them while other hand tried to put clothes back on
• Alien hand syndrome


  • Dr. Strangelove character fighting against his Nazi hand