Split-brain research

• Split-brain research

  a series of studies which began in the 1960s involving people with epilepsy who had experienced a surgical separation of the hemispheres of their brain to reduce the severity of their epilepsy - enabled researchers to test lateral functions of the brain in isolation
• Split-brain research -

  • severing the connections between right hemisphere and left hemisphere
  • epileptic seizure: brain experiences excessing electrical activity which travels from 1 hemisphere to another
  • to reduce these connections are cut so hemispheres cant communicate
• Spilt-brain research - Sperry's procedure

  • 11 people who had a split-brain operation were studies using a special set-up
  • an image projected to a ppts right visual field and same/different image projected to the left visual field
  • 'normal brain' - corpus callosum would share the information between both hemispheres giving a complete picture
  • split brain - information cannot be conveyed from that hemisphere to the other

  
• Split-brain research - Sperry's findings

  • when the picture of the object shown to a ppts RVF (lh) the ppts could describe what was seen
  • when the picture shown to LVF (rh) there was 'nothing there'
  • connected brain - messages from RH are relayed to language centres in the LH
  • they could select a matching object out of sight using their left hand (rh) + select an object that was most closely associated with an object presented to the LVF
  • if pinup picture was shown to LVF - emotional reaction but ppts usually reported nothing or flash of light
• Split-brain research - Sperry's conclusion

  these observations show how certain functions are lateralised in the brain and supports the view that the LH is verbal and the RH is 'silent' but emotional
• AO3 split brain research - research support

  GAZZANIGA - split brain participants perform better than connected controls on certain tasks

  • faster at identifying the odd one out in an array of similar objects than normal controls
  • normal = LH's better cognitive strategies are watered down by RH
• AO3 split brain research - generalisation issues

  causal relationships are hard to establish

  • sperry's ppts were compared to a neurotypical control group - none had epilepsy
  • major confounding variable
  • any difference could have been the result of epilepsy rather than split-brain