Localisation of function

• who is this study partially based around

  phineas gage
• what did scientists originally think about the brain before phineas

  the scientists generally supported the holistic theory of the brain and that all processes and action occured all at once.
• what does localisation of function mean

  different parts of the brain have different responsibilities.
• what is it now assumed to happen if brain damage occurs

  if brain damage occurs to a specific area of the brain the associated function would also be damaged
• what is the brain divided into

  two symmetrical halves, left and right hemispheres
• what does lateralisation mean

  some functions are dominated by one hemisphere
• is activity on the left side of the body dominated by the left hemisphere or right hemisphere


  right hemisphere
• what is the outer layer of the hemisphere called

  cerebral cortex, a 3mm layer covering the inner parts of the brain
• how does the cortex separate us from other animals

  cortex is developed and it appears grey - grey matter
• where is the motor area located and what is its function

  frontal lobe and its responsible for voluntary movements by sending signals to the muscles in the body.
• where is the somato-sensory area located and whats its function

  parietal lobe and its function is to recieve incoming sensory info.
• where is the visual area located and whats its function

  located in the occipital lobe, and its function is to recieve and process visual information.
• where is the auditory area located and whats its function

  located in the temporal lobe and its function is to analyse and process acoustic information
• where is the brocas area located and what is its function

  located in the left frontal lobe and is involved in language production
• where is the wernickes area located and what is its function

  located in the left temporal lobe and is involved in language comprehension
• What is the strength of localisation of function

  tulving 1994 found evidence using PET scans that are semantic and episodic memories reside in different parts of the pre-frontal cortex.

  semantic in the left hemisphere and episodic in the right.
• whats a weakness of the localisation of function

  lashley 1950 removed differing percentages of the cortex from rats brains and in different places - between 10 and 50%.

  The rats then had to learn to navigate a maze.
• what did lashley find?

  the rats with the most cortex removed learned the slowest.

  no area proven to be more important than another area for the rats learning.

  therefore rats dont have localised functions. their whole brain is their whole function. so its not applicable to everyone (only rats).
• What's another weakness of localisation of function

  not all researchers agree with the view that cognitive functions are localised in the brain.

  the work from lashley suggests basic motor and sensory functions were localised but that higher mental functions were not.

  lashley claimed that intact areas could take over responsibility for damaged areas, so according to this the damage would be determined by the extent rather than the location of the damage.

  therefore functions arent localised.
• What's the strength of this study

  brain scan evidence

  there is evidence that many neurological functions are localised, particularly in relation to language and memory.

  peterson 1988 used brain scans to demonstrate how wernickes area was active during a listening task and brocas area was active during the task suggestinf these areas are localised.

  therefore there is scientific backing
• whats a strength of this study

  neurosurgical evidence.

  the most extreme type of treatment involves surgically removing healthy brain tissues - lobotomy/leucotomy

  the success of these procedures strongly suggest that symptoms associated with serious mental disorders are localised.

  therefore assumes those areas are linked with specific conditions and their localised.