Hemispheric lateralisation

• Localisation = very specific areas in the brain govern some functions such as vision and language

  Lateralisisation = There are two sides which are called hemispheres

  For some functions, the localised areas appear in both hemispheres
• Left and right hemispheres (language) - hemispheric lateralisation

  • for language the two main centres are only in the left hemisphere (Brocas + Wernickes) - language is lateralised
  • right hemisphere can only produce rudimentary words and phrase but has emotional content
  • Left hemisphere = analyser
  • Right hemisphere = synthesiser
• Left and Right hemisphere (motor) - hemispheric lateralisation

  • vision, motor and somatosensory areas appear in both hemispheres
  • motor area = brain is cross-wired

  RH - left side LH - right side
• Left and right hemispheres (vision) - hemispheric lateralisation

  • contralateral and ipsilateral (opposite and same-sided)
  • each eye receives light from the left visual field and the right visual field
  • LVF of both eyes = RH
  • RVF of both eyes = LH
  • enables visual areas to compare different perspectives from each eye - aids depth

  
• hemispheric laterlisation

  The idea that the two hemispheres of the brain are functionally different and that certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other e.g language
• AO3 hemispheric lateralisation - lateralisation in the connected brain

  • research shows that even in connected brains the two hemispheres process information differently
  • Fink - used PET scans to identify which brain areas were active during a visual processing task.
  • participants with connected brains asked to attend to global elements of an image -> regions of RH active
  • focus in on finer detail -> specific areas of LH active
  • hemispheric lateralisation is a feature of connected brain and split-brain
• AO3 hemispheric lateralisation - one brain

  • research suggests people do not have a dominant side of their brain which creates a different personality
  • Nielsen - analysed brain scans from over 1000 people aged 7-29 and found people used certain hemispheres for certain tasks
  • but no evidence for the dominant side
  • notion of left/right brained people is wrong