A03

• Negative plasticity

  • one limitation of plasticity is it may have negative behavioural consequences
  • evidence shows Brain's adaption to prolonged drug use which leads to poorer cognitive functioning in later life + increased dementia
  • 60-80% of amputees develop phantom limb syndrome - continued sensations in missing limb as if it were still there.
  • Brain's ability to adapt to damage is not always beneficial.
• support from human studies

  • Maguire and taxi drivers discovered that changes in brain could be detected as a result of their extensive experience of spatial navigation
  • MRI scanner, researchers calculated grey matter in brains of taxi drivers and set of control participants
  • posterior hippocampi of taxi drivers were larger relative to those of control participants and posterior hippocampal volume has positively correlated with amount of time they spent as a taxi driver
• support from animal studies

  • kempermann suggested an enriched environment could alter number of neurons in brain.
  • they found evidence of increased number of new neurons in brains of rats housed in complex environments compared to rats housed in laboratory cages.
  • rats housed in complex environment showed an increase in neurons in hippocampus
• Age differences in functional recovery

  • commonly accepted view that functional plasticity reduces with age
  • Only option following traumatic brain injury beyond childhood ia to develop compensatory behavioural strategies to work around the deficit.
  • studies have suggested that even abilities commonly thought to be fixed in childhood can still be modified in adults with intense retraining