localisation of function

• localisation of function- certain areas of the brain are associated with certain cognitive functions eg memory
• motor cortex

  • located in the frontal lobe along pre-central gyrus
  • responsible for movement
  • different parts control different parts of the body and are arranged logically
  • both hemispheres have motor cortex but control the opposite side of the body eg left hemisphere controls the right side of the body
  • highly localised
• somatosensory cortex

  • located in the perietal lobe along a region called the post central gyrus
  • processed touch
  • both hemispheres have somatosensory cortex with them receiving information from opposite sides of the body
  • more sensitive= larger region of somatosensory cortex eg hands
  • arranged logically
  • highly localised
• auditory centres

  • located in the auditory cortex in the temporal lobes
  • sound waves picked by cochlea, converted to nerve impulse to the brain stem then to thalamus which is relay station and then to auditory cortex
  • not localised
• broca's area

  • responsible for speech production
  • located in the frontal lobe on the left hemisphere
  • broca's aphasia- difficulty speaking
  • case study- Tan couldn't speak or write but could understand spoken language. could only say one syllable Tan
• wernicke's area

  • located in the temporal lobe
  • responsible for understanding language
  • wernicke's aphasia- condition where patients can't understand language but can still speak
• • research support from brain-damaged patients.
  • patient Tan experienced Broca’s aphasia following damage to his Broca’s area, where his speech production was impaired and he could only say the syllable ‘Tan’.
  • This matters because it suggests that research on the language centre of the brain supports the idea that certain cognitive functions are localised to specialised brain regions.
  • the idea of localisation of function has validity.
• • that language may not be confined to broca's area only
  • dronkers re-examined the brain of two of brocas patients using MRI scans and he found that other areas besides broca's are has contributed to loss of speech
  • matters because language is way more complex than being localised to one brain region and instead involves many interactions of several brain regions
  • biologically reductionist
• • localised of function has been challenged by lashley's equipotentiality theory
  • theory suggests that basic motor and sensory functions are localised while higher mental functions are not
  • lashley's research was based on his work with rats, where he removed areas of their cortex and had them learn to run a maze. he found all areas of the cortex were important in the task
  • researchers should take a holistic approach when studying cognitive functioning