Evaluation

• Research support - Case study


  • Phineas Gage
  • Iron rod penetrated his skull and damaged his frontal lobe
  • His personality changed significantly - he became impulsive and struggled with social interaction
  • His physical abilities and memory remained intact - provides evidence of the brain's compartmentalisationo
• Counterpoint to Phineas Gage


  • Not generalisable - very rare and unreplicable
  • The infection may have damaged other areas of the brain - cannot pinpoint which area caused his changes
  • Therefore, it cannot definitively support localisation theory
• Language localisation questioned


  • Dick and Tremblay - only 2% of modern researchers think that the brain is controlled completely by Broca's area and Wernicke's area
  • Advances in brain scan technology such as fMRIs mean neural processes can be studied much more clearly
  • Language function is distributed more holistically than thought - language streams have been identified across the cortex
  • This therefore contradicts localisation theory
• Research against localisation


  • Lashley - trained rats to navigate a maze
  • Systematically removed different parts of their cortices (between 10-50%)
  • Found that no single brain region was solely responsible for the rats’ ability to learn or recall the maze
  • Proposed principle of ‘equipotentiality’ - surviving brain circuits ‘chip in’ so the same neurological action can be achieved
  • Therefore, complex functions like memory rely on networks