lateralisation and localisation A03

• • biologically reductionist

  -research = not localised or lateralised 

  • (loc) lashleys’ equipotentiality theory - higher mental processes are not localised and intact areas of cotrtex can take of functions from damaged areas
  • studies of  humans able to regain cognitive abilities following damage to area 
  • Jodie - half brain removed and functions normal
  • functions may not be as specifically localised/lateralised as was first suggested 
  • Homologous brain adaptation functions aren’t lateralised fixed = plasticity
• localisation - Derjine reported case

  • man lost his ability to read, following damage to the connection between the visual cortex and the Wernicke’s area.
  • This suggests that interactions between different areas produce complex behaviours such as language.
  • Therefore, damage to the connection between any two points can result in impairments that resemble damage to the localised brain region associated with that specific function
  • idiographic
• • case study evidence - Broca’s aphasia = impaired ability to produce language; caused by brain damage in Broca’s area. 

  • Wernicke’s aphasia = impairment of language perception, important role played in the comprehension of lang
  • Dronkers MRI scan on patient Tan’s preserved brain, to try confirm Broca’s findings.
  • Although lesion found in Broca’s area, evidence to suggest other areas may have contributed to failure in speech production.
  • Broca’s area not only region responsible for speech production and deficits found in aphasia patients could be due to damage to neighbouring regions
• Changed with age-lacks populational validity 

  Szalfaski found that language becomes more lateralised to the left increasing with age in children and teens but after 25 became less lateralised

  Lacks populational validity 

  Can’t assume it is the same for all ages 
• Split brain research - idiographic confounding variables-medicine and epilepsy 

  Andrewes pointed out that most studies are less than 3 or even just one participant

  Those participants have confounding physical disorder or in some of them not all was cut 

  They have also took much medication