localisation of function in the brain

• what is localisation of function?

  theory that different areas of the brain are responsible for specific behaviours processes or activities
• what is the motor area?

  region of the frontal lobe involved in regulating movement
• what is the somatosensory area?

  area of the parietal lobe that processes sensory information like touch
• what is the visual area?

  part of the occipital lobe that receives and processes visual information
• what is the auditory area?

  located in the temporal lobe and concerned with the analysis of speech based information
• what is Broca's area?

  area of the frontal lobe in the left hemisphere responsible for speech production
• what is wernicke's area?

  area of the temporal lobe in the left hemisphere responsible for language comprehension
• strength of localisation theory?

  p- damage to areas of brains linked to mental disorders

  e- cingulotomy is isolating region called cingulate gyrus which is implicated in OCD.

  e- Dougherty et al reported on 44 people with OCD who had a cingulotomy. at post surgical follow up after 32 weeks, 30% met criteria for successful response to surgery and 14% for partial response.

  l- success of these procedures suggests behaviours associated with serious mental disorders may be localised
• another strength of localisation theory?

  p- evidence from brain scans supporting idea that everyday brain functions are localised.

  e- Petersen et al used brain scans to demonstrate how wernicke's area was active in a listening task and Broca's area was active in a reading task.

  e- confirms localised areas for everyday behaviours.

  l- objective methods for measuring brain activity provided sound scientific evidence that brain functions are localised.
• CA for another strength of localisation theory/ evidence

  p- lashley challenges the localisation theory

  e- lashley removed areas of the cortex in rats learning the route of a maze.

  e- no area proven more important than other areas in terms of rats ability to learn and process of learning required every part of cortex.

  l- higher cognitive processes aren't localised but distributed in more holistic way.
• limitation of localisation theory

  p- language may not be localised just to Broca's and wernicke's area

  e- dick and Tremblay found only 2% of modern researchers think language in brain is completely controlled by broca's and wernicke's areas. Brain imaging techniques help neural processes to be studied more clearly. so language function in brain distributed more holistically.

  l- so language may be organised more holistically in brain which contradicts localisation theory.
• what is the case of Phineas gage?

  gage was working in a railroad and he dropped his tamping iron on rock causing explosive to ignite. pole went through gages skull, taking some of his brain away.

  turned to someone who was calm and reserved to rude and quick tempered