Localisation of function

• Localisation of function

  The belief that different areas of our brain are associated with specific cognitive processes
• Broca’s area

  An area in the frontal lobe, usually left hemisphere, related to speech production
• Wernicke’s area

  An area of the temporal lobe of the brain important for comprehension of language
• There’s a neural link between both Broca and Wernicke’s areas
• The brain - external cerebral cortex

  • Frontal lobe - thought, planning, motivation and speech production
  • Parietal lobe - Motor movements and sensory information
  • Temporal lobe - language comprehension, hearing and memory
  • Occipital lobe- Visual processing
  • Brainstem - helps control our heart rate, blood pressure, swallowing and breathing
  • Cerebellum - helps coordinate balance and fine muscle movements
• The Brain - internal

  • Thalamus - relay station for nerve impulses from the sense
  • Hypothalamus - regulates body temperature, hunger and thirst. Links the endocrine and nervous system together. Also controls the release of hormones from the pituitary gland
  • Hippocampus - Holds STM and transfer these to the LTM storage. It also aids emotional response and anxiety
  • Corpus Callosum - responsible for transferring from one hemisphere to the other
• The visual cortex in the occipital lobe is the centre of visual information

  1. Light enters the retina and strikes the photo receptos
  2. The retina sends nerve impulses to areas of the brain that coordinates circadian rhythms, mostly the thalamu
• The visual cortex spans both hemispheres and has several different sections that process different visual information (colour, shape, movement)
• The temporal lobe is responsible for processing auditory information (the auditory cortex)

  1. Auditory information is received by the cochlea in the inner ear, converting sound waves to nerve impulses which travel to the brain
  2. When it reaches the brain stem information is decoded into intensity and duration
  3. The nerve impulses then travels to the thalamus - the relay station for further processing
• The somatosensory cortex


  Detections of changes along post central gyrus - processes sensory information relating to touch
• Weakness - Lashley (1930)

  • localisation of function does exist for simple processing, but not for higher mental functionings
  • Intact areas of the brain may take control when others have been damaged, but this depends on the extent of the damage
  • Gave rats lesions on their brains and investigated their behaviour
• Weakness - LOF or communication across brain - Joseph Degerine (1892)

  • Loss of ability to read is due to damage of connection between the visual cortex and Wernicke’s area
  • Thus suggesting that complex processing gradually builds up and takes place between structures before a response is produced
  • Damage to the connection between these structures may result in impairment
• Weakness - is language confined to Broca’s area - Droner et al (2007)

  • When reviewing the preserved brain of Tan (Louis Lebonge) and Lazare Lelong, using MRI, it was found that other areas of the brain were damaged, suggesting that this may also have contributed to their speech impairments
  • However, damage to Broca’s area rarely resulted in severe damage, suggesting its far more complex
• Strength - Phineas Gage 1848 (studied by Harlow)

  • gage was a ‘tamper’ during construction of the US railroads, one day an explosive ignited in a rock and a rod was propelled through Gage’s skull
  • He survived, it grew to be impulsive, rude and incapable of reason, alienated his friends and ‘was no longer gage’
  • This shows the frontal lobes are responsible for personality and reasoning
• Weakness - Individual differences - Braveller et al (1997)

  • Found unique patterns of activity in individuals, finding they varied in frontal, temporal and occipital lobe
  • Other studies also found gender differences in the size of both Broca’s and Wernicke’s area