plasticity + functional recovery

AO1

plasticity

• describes the brain’s ability to change and adapt because of the experience and new learning

• structural plasticity - changes in brain structure such as increasing grey matter due to learning. this is most seen during infancy, where the brain grows rapidly and forms many synaptic connections

• as we age, unused connections are deleted and frequently used ones are strengthened. this is called synaptic pruning

functional recovery

• following damage through trauma, the brain can redistribute or transfer functions to other areas of the brain which are undamaged

• this process can occur quickly after trauma and then slow down after time

  • axonal sprouting - undamaged axons grow new nerve endings to reconnect neurons whose links were injured or severed

  • denervation supersensitivity - axons which complete similar jobs become aroused to compensate for the loss of other axons

  • recruitment of homologous areas - areas on the opposite sides of the brain take on the function of a damaged area

  • neuronal unmasking - dormant synapses open connections to compensate for damaged area

AO3

• one strength of plasticity is that it has a wealth of supporting research

• maguire et al conducted a study on the hippocampal volume of london’s taxi drivers

• it was found that their hippocampi had more grey matter compared to controls. this was likely a result of the drivers having to memories many complex routes and streets throughout the city.

• it was further found that the more experienced the drivers were, the more pronounced this difference wad

• this supports theories that the brain is plastic and physically changes according to experience

• a further strength of plasticity is that it can be used to help develop rehabilitation.

• by understanding that the brain can increase plasticity, the development of new treatment is encouraged as researchers understand that the brain is able to recover. for example, motor therapy and electrical stimulation of the brain was developed to counter the diminishing of motor/cognitive functions following accidents or strokes

• this shows that plasticity and functional recovery are useful for the healthcare field and that it can be used to make effective intervention, potentially helping many people

• one limitation of plasticity and functional recovery is that it does not always seem to occur

• plasticity suggests that other parts of the brain are able to tale over function upon injury. however, HM had large portions of his hippocampus removed resulting in his short term memory being damaged but was never able to recover

• this suggests that plasticity is not a universal trait, or at least that it’s functioning is more complex than simply occurring after trauma

• this suggests a more idiographic approach must be taken regarding functional recovery, as individual differences seem to exist

• this is only further seen as research seems to suggest that time spent in education is positively correlated with disability-free recovery, highlighting individual differences affecting plasticity.

• therefore, one could argue that current understanding of plasticity is limited

• a strength is that there is supporting research

• ramachandran conducted studies with amputees where 60-80% said they experience phantom limb syndrome

• thought to be due to cortical reorganisation in the somatosensory cortex

• supports idea of plasticity, brain is rewiring

• but has negative behavioural consequence, very painful and uncomfortable