Localisation of brain function

• Localisation of function

  > Specific areas of the brain are specialised for certain functions - motor cortex is responsible for voluntary movement.
• Broca's area -

  > production of spoken and written language

  > damage can cause brocas aphasia - slow speech that lacks fluency - meaningful speech is effortful
• Motor cortex - both hemispheres

  > creation of voluntary motor movements

  > Damage can mean loss of control of fine movements or paralysis - contralaterally wired
• Somatosensory cortex - both hemispheres

  > Processes information from the senses in the skin, including touch, pressure, pain and temperature

  > Damage can cause issues perceiving touch, failure to recognise object by touch
• Visual cortex - both hemispheres

  > Receives information from eyes - RVF - LH and LVF - RH

  > Processes information such as colour and shape

  > Damage can cause blindness, hallucinations or an inability to see colour or motion
• Wernicke's area - left hemisphere

  > Involved in the understanding of language

  > Damage can cause Wernicke's aphasia - nonsense words but fluent
• Auditory cortex - both hemispheres

  > Analyses speech eg. pitch and volume

  > Damage can cause hearing loss partial or full
• Localisation of brain function AO3

  :) RTS Broca

  :( RTC case study of EB

  DISCUSSION both lack population validity

  :( RTC Lashley
• Localisation of brain function AO3

  :) RTS Broca

  > Reported the case study of the man who could only say 'tan' even though he could understand language

  > Post mortems showed damage to one area of his left hemisphere which is now named Brocas area

  > This shows that language production is localised to one specific brain area as the theory predicts
• Localisation of brain function AO3

  :( RTC Case study Patient EB

  > EB suffered brain damage and had his left hemisphere removed and therefore his language centres

  > After some time patient EB regained some of his language abilities that would not be possible if language was completely localised to the left hemisphere

  > This demonstrates that language must be in more areas then just the left hemisphere, suggesting a holistic explanation is more appropriate then localisation of brain function
• Localisation of brain function AO3

  CASE STUDIES

  :( Lack population validity

  > May not be appropriate to generalise the findings on the localisation of function to the typical population as they are unique cases with brain damage

  > Brain damage may have affected the way in which the brain functions and some individuals may be able to process language in other areas of the brain

  > Therefore suggesting more research is needed with more diverse samples before firm conclusions can be made
• Localisation of function AO3

  :( RTC Lashley

  > Lashley removed areas of the cortex in rats that were learning a maze

  > It was found no area was more important than any other area in terms of the rats ability to learn the maze

  > The process of learning required all areas of the cortex rather then one specific area of the brain

  > Therefore, this suggests that a holistic explanation of the brain may be more appropriate than suggesting the brain is localised in function