Localisation of Function in the Brain

• Holistic


  Concerning the whole rather than the parts
• Localisation of function


  The theory that different areas of the brain are responsible for different behaviours, processes or activities.

  
• Lateralisation


  The dominance of one hemisphere of the brain for particular physical and psychological functions

  
• Motor area


  A region of the frontal lobe involved in regulating movement

  
• Somatosensory area


  An area of the parietal lobe that processes sensory information such as touch

  
• Visual area


  A part of the occipital lobe that receives and processes visual information

  
• Auditory area


  An area of the temporal lobe that interprets hearing

  
• Broca's area


  Controls language expression - an area of the frontal lobe, in the left hemisphere, that directs the muscle movements involved in speech.

  
• Wernicke's area


  Controls language reception - a brain area involved in language comprehension and expression, in the left temporal lobe

  
• Strengths of localisation of function

  Evidence from neurosurgery

  - Dougherty et al reported on 44 people with OCD who had undergone a cingulotomy.

  - At post-surgical follow-up after 32 weeks, about 30% met the criteria for successful response to the surgery and 14% for partial response.

  
  

  Evidence from brain scans

  - Peterson et al used brain scans to demonstrate how Wernicke's area was active during a listening task and Broca's area was active during a reading task.

  - Bucker and Peterson revealed that semantic and episodic memories reside in different parts of the prefrontal cortex.
• Limitations of localisation of function

  Language localisation questioned

  - Dick and Tremblay found that only 2% of modern researchers think that language in the brain is completely controlled by Broca's and Wernicke's areas.

  - Advances in brain imaging techniques mean that neural processes in the brain can be studied with more clarity than ever before.

  - So-called language streams have been identified across the cortex as well as in subcortical regions such as the thalamus.