Split Brain Research

Learning about

right brain/left brain differences


Function of the corpus callosum


      Seizure – period of excessive neural activity  in brain or brain area

      Epilepsy - Recurring seizures; about 1-2 in 100 people has epilepsy;  ccurs in many forms

      May be inherited or or may follow some injury to the brain

      In the latter case, seizures usually begin at the injured spot (the “focus”) and it is called “focal  or partial seizure”.  Because the brain is so conductive, partial seizures may spread


Visual Fields

      Each half of your brain sees the opposite half of your visual world

      Similarly, each half of the brain senses and moves the opposite half of the body.


Roger Sperry – Testing of
Split Brain Patients
Left Brain Sees a Ball

      “I see a baseball”

Right Brain Sees a Hammer

      “I see nothing”

      But left hand can select the hammer, indicating hammer was perceived but couldn’t be verbally identified by right hemisphere.


      This is evidence for “lateralization of function” – that is, one side of the brain having different functions/abilities than the other side.


Left: Language, mathematics, analytical/detail

Right: Visual/spatial processing, interpreting nonverbal sounds, voice intonation, music, recognizing and expressing emotion.


Left Hemisphere
Subjective Interpreter

      Gazzaniga proposes the LH provides our inner voice narrative interpretation as we try to make sense of the world, the verbal reconstruction of our memories.



Aphasia: language problems due to brain damage

      The greater the damage in the vicinity of Broca’s area, the greater the difficulty producing speech: “Broca’s aphasia”

   Both spoken & signed; affects writing & gesturing too

   Affects the use & understanding of grammatical words, endings, & meaning conveyed by word order

   Results in “telegraphic speech” (nouns & verbs)

      Damage to Wernicke’s area disrupts memory of words & speech comprehension/comprehensibility: “Wernicke’s aphasia” Can talk but not make sense.