Localisation of Function

• What is the Holistic Theory?


  The theory that all parts of the brain are involved in thought processes and action
• Localisation of Function


  The theory that different areas of the brain are responsible for different functions and behaviours
• What are the 4 lobes?

  1. Frontal Lobe
  2. Parietal Lobe
  3. Occipital Lobe
  4. Temporal Lobe
• Frontal Lobe


  Responsible for movement, personality and higher level thinking (problem solving)
• Parietal Lobe


  Responsible for processing information from our senses. Controls memory and their uses
• Temporal Lobe


  Responsible for hearing, speech and memory
• Occipital Lobe


  Responsible for receiving and processing visual information
• Motor Area


  Responsible for controlling movements. Is found in the frontal lobe
• Somatosensory area


  Receives sensory messages such as touch and pain from the rest of the body. Found in the parietal lobe
• Auditory area


  Responsible for analysis of speech related information. Found in the temporal lobe.
• Visual Area


  Processes visual information. Found in the occipital lobe
• What is Aphasia?


  When someone has lost the ability to understand or produce speech
• Paul Broca

  • French physician and surgeon
  • Broca met a patient who had problems with speech and could only say 'Tan'
  • Broca then studied their brain to find damage to the Left Frontal Lobe
• Broca's Area

  • Found in the left hemisphere
  • In the left frontal lobe
  • It is responsible for speech production
• What is Broca's Aphasia?

  An impaired ability to produce language caused by damage to Broca's area
• Karl Wernicke

  • Identified patients that had no problem producing speech but had problems understanding speech
  • He found damage to the left temporal lobe
• Wernicke's Area

  • Found in the left hemisphere
  • In the left temporal lobe
  • Responsible in understanding written and spoken language
• Wernicke's Aphasia


  Impaired ability to comprehend language caused by damage to Wernicke's area
• Brain


  labelled

  
• AO3: Brain Scan Evidence of Localisation

  Researcher 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 suggesting different areas of the brain have different functions
• AO3: Patient HM

  • Suffered a bike accident that gave him epilepsy and had his hippocampus removed which gave him amnesia
  • He could not form new memories but could remember before the surgery
  • This provides evidence for the localisation of function as the hippocampus may play a part in forming new memories
• AO3: Neurosurgical Evidence

  • Lobotomy - operation done to the prefrontal lobe to treat mental illness
  • It is used rarely in severe cases of OCD and depression
  • 44 people had undergone surgery and 1/3 had met the criteria for successful response and 14 % for partial response
  • The success of these procedures suggest that symptoms and behaviours associated with mental disorders are localised
• AO3: Lashley's Research

  • Lashley suggests that higher cognitive functions such as learning are not localised but distributed in a more holistic way
  • Lashley removed areas of the cortex in rats
  • No area was proven to be more important than any other area
  • This suggests that learning is too complex to be localised and requires the whole brain
• AO3: Plasticity

  • An argument against localisation of function is plasticity
  • This is when the brain has become damaged and a particular function becomes compromised or lost and the brain attempts to reorganise itself in an attempt to recover the lost function
  • This goes against localisation of function that says different parts of the brain have specific functions
• AO3: Generalisability


  Research to support localisation have been extremely rare case studies. This makes the research hard to generalise to the wider population.