Localisation of function

• localisation of function: The theory that different areas of the brain are responsible for specific behaviours, processes or activities.
• 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: Located in the temporal lobe and concerned with the analysis of speech-based information.
• Broca's area: An area of the frontal lobe in the left hemisphere, responsible for speech production.
• Wernicke's area: An area of the temporal lobe in the left hemisphere, responsible for language comprehension.
• Hemispheres of the brain:

  • The main part of the brain is divided into two symmetrical halves.
  • Some of out physical and psychological functions are controlled by a particular side of the brain.
  • Language is linked to the left hemisphere.
• What are the four lobes in the brain?

  frontal, parietal, occipital and temporal.
• At the back of the frontal lobe is the motor area which controls movement. Damage to this area may result in loss off control over fine movements.
• The somatosensory area is where sensory information from the skin is represented.
• Damage to broca's area causes Broca's aphasia, the person can't articulate their thoughts. E.G. 'Tan' could only say the word tan, even though he may have been able to think of what he wanted to say he couldn't say it.
• Damage to Wernicke's area results in people producing 'nonsense words' as they can't think about what they want to say. It affects language comprehension.
• Evaluation: localisation of function (Strength)-

  • Evidence from neurosurgery
  • Damage to area of the brain have been linked to mental disorders.
  • Neurosurgery is a last resort method for treating some mental disorders, targeting specific areas of the brain.
  • The success from procedures suggests behaviours associated with serious mental disorders may be localised.
• Evaluation: localisation of function (Strength)-

  • Evidence from brain scans
  • Petersen et al used brain scans to demonstrate how Wernicke's area was active during listening tasks and Broca's area was active during a reading task.
  • Objective methods for measuring brain activity have provided evidence that many brain functions are localised.
• Evaluation: localisation of function (limitation)-

  • Evidence from brain scans counterpoint.
  • Lashley removed area of the cortex in rats that were learning a route through a maze.
  • No area was proven to be more important than any other in terms of the rats ability to get through the maze.
  • This suggests that higher cognitive processes such as learning are holistic.
• Evaluation: localisation of function (limitation)-

  • Language localisation questioned.
  • Language may not just be limited to Broca and wernickes's area.
  • Through FMRIs it seems that the language function is more holistic
  • This contradicts the localisation theory.