Hemispheric Lateralisation and Split Brain

• Hemispheric lateralisation - the left and right hemisphere of the brain are responsible for different functions.

  > left - language and logic

  > right - recognition and creativity
• Left Hemisphere:

  > responsible for language

  > contain the two main language centres - Broca's area and Wernicke's area
• Right Hemisphere:

  > responsible for recognition of faces, places and objects, and creativity

  > can only produce rudimentary words and phrases, but contributes to the emotional context of what is said
• > Many functions are not lateralised (vision, motor and somatosensory areas) as they occur in both hemispheres

  > Brain has contralateral wiring
• Hemispheric Lateralisation AO3:

  :) RTS - Sperry

  BUT individual differences

  :( RTC - patient EB

  BUT low population validity
• Split Brain:

  > surgery that severs the connection between the two hemispheres - corpus callosum - normally to treat epilepsy

  > the two hemispheres become functionally separate
• Split Brain Research - Sperry :

  > natural experiment with 11 individuals who had their corpus callosum severed through surgery

  > participants sit in front of a screen and fixate their gaze on a spot in the middle

  > presented with visual information to either their right or left visual field for 1/10th of a second (not enough time to switch focus)

  > objects seen in the RVF can be named verbally and an in writing, as it was processed by LH, whereas, objects seen in LVF can only be identified through pointing but not named
• Split Brain Research AO3:

  :) Scientific methods

  :( Individual differences - degree to which corpus callosum was severed

  :( Causal relationship is hard to establish - compared to neurotypical control group

  :( RTC - patient EB