Plasticity and functional recovery of the brain

• brain plasticity refers to the brains ability to change and adapt as a result of experience
• within plasticity, the brains ability to change plays a huge role in brain development and behaviour
• recent research demonstrates brain continues to create neural pathways and alter existing ones to adapt to new experiences as result of learning

  • therefore disagrees with researchers who used to believe changes in brain used to only take place in infancy and childhood
• causes of plasticity

  • life experiences
  • video games
  • meditation
• what are the causes of plasticity?


  life experiences, video games and meditation
• life experiences being a cause of plasticity

  • people gaining new experiences, nerve pathways which develop stronger connections
  • with aging there is a natural decline in cognitive functioning - led researchers to look for ways new connections can be made to reverse effect
  • example - boyke et al found evidence of brain plasticity in 60 year olds who were taught to juggle - in form of increased grey matter in visual cortex (changes were significantly reversed)
• video games being cause of plasticity

  • video games make many different complex cognitive and motor skills
  • kuhn et al compared control group to video training group that was trained for 2 months for 30 min day on super mario - found significant increase in grey matter in various areas including the hippocampus
  • researchers concluded video games resulted in new synaptic connections in brain areas involved in spatial navigation and strategic planning
• meditation being a cause of plasticity

  • davidson compared 8 practitioners of tibetan meditation with 10 student volunteers (no experience in meditation)
  • through electrical sensors - found greater gamma wave activation in the monks than students when meditating
  • researcher concluded meditation not only changes workings of brain in short term but also produced permanent changes
• functional recovery after trauma (brain adapting as result of experience)

  • 1960s researchers studied cases which stroke victims were able to regain functioning
  • discovered when brain cells are damaged or destroyed - brain rewires over time so some level of functioning can be regained
  • although parts of brain are damaged or destroyed as result of trauma - other parts appear to take over functions that were lost
  • neurons next to damaged brain areas can form new circuits resuming some of the lost function - brain adapting to change due to experience of trauma
• mechanisms for recovery

  • neuronal unmasking
  • stem cells
• evaluation - strength - research support

  • there is research to support from animal studies
  • kempermann et al investigated whether an enriched environment could alter the number of neurons in the brain of rats - found those housed in complex environments had increased number of neurons in hippocampus in comparison to those in lab cages
  • supports plasticity of how brain - shows how environmental factors can lead to changes in development of neural pathways
  • also important to recognise the limitation of animal studies
• evaluation - strength - research to support

  • also supported by research into plasticity in humans
  • maguire et al found london taxi drivers have much larger posterior hippocampus compared to control group and size was positively correlated with amount of time spent as taxi driver
  • supports plasticity as it shows complex memory training (taxi drivers memorising huge areas) can cause changes in certain areas of brain
  • supported by research increasing validity of the theory
• evaluation - strength - research support for functional recovery

  • functional recovery after trauma is supported by research from animals
  • tajiri et al gave transplants of stem cells into regions of brain affected by traumatic injury and found in brains of rats in stem cell group there was clear development of neuron like cells in area of injury - and solid stream of stem cells migrating to brains site of injury
  • therefore indicates the role of stem cells in regaining brain functioning
  • strength - research to support but need to consider limitations of animal research
• evaluation - limitation - harder to make changes as age

  • ability of the brain to recover from trauma varies with age
  • studies suggested abilities thought to be fixed in childhood can still be modified in adults with intense training
  • despite indications of adult plasticity - elbert et al concluded the capacity of neural reorganisation is much greater in children than adults as demonstrated by extended practice that adults require in order to produce changes
  • limitation is the older the individual is when trauma occurs the more challenging it is to make and maintain changes
• evaluation - strength - data from humans to support recovery

  • strength of functional recovery is there is research to support which has shown educational attainment can have effect on recovery after traumatic brain injury
  • schneider et al found patients with equivalent of college education are 7 times more likely to be disability free a year after moderate to traumatic brain injury to those who dont finish school
  • important as suggests those engaging in further education were in an environment that encourages development of neural pathways - aiding in their ability to recover from brain injury
• how do individuals functionally recover from trauma?

  through stem cells and neural unmasking
• stem cells are unspecialised cells that give rise to different cell types that carry out functions (taking on characteristics of nerve cells)

  • 1 view - stem cells implanted to brain would directly replace dead/dying cells from trauma
  • 2 view - transplanted stem cells secrete growth factors that 'rescue' injured cells
  • 3 view - transplanted cells from neural network linking injured brain site - where new stem cells are made within damaged region of brain
• neural unmasking is where 'dormant synapses' (those which dont receive enough input to be active) open connections to compensate for damage area of brain.
• neural unmasking

  • wall first identified 'dormant synapses' in brain - synaptic connections that exist automatically but function is blocked
  • under normal circumstances - synapses may be ineffective because rate of neural input too low for them to be activated - increasing rate of input to synapse can open dormant synapses
  • opening dormant synapses can open connections to regions of brain which arent normally activated - creating spread of activation and gives way to development of new structures