plasticity & functional recovery of the brain after trauma

• plasticity 


  the brains tendency to change and adapt its structure and function as a result of experience and new learning
• researchers used to believed that changes in the brain only took place during infancy and childhood - recent has demonstrated that the brain continues to create new neural pathways and alter existing ones
• the more a person performs an activity the more neuronal connections are formed in the area of the brain reasonable
• factors effecting structure and function


  life experience, juggling, video games and meditation
• background of Maguire study 


  london taxi drivers undertake special training that tales 2 years to complete, learning to navigate their way around centeral london without a map - ' on the knowledge'
• Maguire hypothesis 


  fully licensed London taxi drivers will have structural differences in their hippocampus as a result of this learning experience
• procedure 


  brain scans of 16 healthy, right-handed male licensed London taxi drivers vs with the scams of 50 healthy right-headed males who didn't drive taxis

  mean ages = 44 , range of ages = 32-62

  using an MRI scanner in the researchers calculated the amount of grey matter in the P's brain
• findings


  taxi drivers had significantly more grey matter in the posterior hippocampus than the control

  both L and R hippocampus were significantly higher in volume in taxi drivers brains

  positive correlation between volume of the hippocampus and time spent as a taxi driver - couldn't be accounted for by age differences
• conclusion


  the hippocampus is associated with memory and the development of spatial skills

  taxi drivers have a redistribution of grey matter in the hippocampus because of intense development and use of spatial memory skills - therefore the environment can influence brain structure = supporting the idea of plasticity
• supporting evidence

  Kuhn et al compared a control group with a video game training group who trained for 2 months for 30mins plus a day on the game Super Mario - found increase in grey matter in the Super Mario group in brain areas including the motor cortex, hippocampus and cerebellum - concluded video game training resulted in new synaptic connections in brain areas involved in spatial navigation, strategic planning, working memory and motor performance
• supporting evidence 


  Draganski imaged medical students brains 3 months before and after their final exams - found that learning included changes could be seen in the posterior hippocampus, as a result of the exam
• positive implications


  research helps us understand effects of the environment on the brain , brains ability to rewire itself can sometimes have maladaptive behavioural consequences = negative plasticity

  prolonged drug use = poorer cognitive functioning as well as an increased risk of dementia later in life = understanding this means that advice and treatment can be developed
• functional recovery 


  form of plasticity - brains ability to redistribute/transfer functions usually performed by a damaged area to an undamaged area - happens after a trauma has occurred - neuroscientists suggest that the process can occur quickly after a trauma , then slows down for weeks or months - then individual may require rehabilitative therapy to further their recovery
• neuronal activation


  brain is able to rewire and reorganise itself by forming new synaptic connections close to the area of damage , secondary neural pathways that would not typically be used to carry out the functions are activated to enable functioning to continue
• neuronal activation - supporting evidence

  structural changes in the brain :

  axonal sprouting - growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

  reformation of blood vessels

  recruitment of similar areas on the opposite side of the brain
• strength - positive applications

  contributed to the field of neuro-rehabilitation , forms of physical therapy might be required to maintain improvements in functioning - techniques include movement therapy and electrical stimulation of the brain = shows that although brain may have capacity to fix itself to a point, this process requires further intervention to be completely successful
• weakness - individual differences 


  cant be applied to everyone equally , there has been individual differences in how well the brain adapts after injury

  evidence = a persons educational attainment might influence how well the brain recovers - p's with a uni education are 7 times more likely than those who didn't finish high school to be disability free 1 year after a moderate-severe brain injury = educational attainment could be a factor in a neural adaptation during recovery from brain injury
• age differences in plasticity - individual differences 


  plasticity and recovery reduces with age - brain has greater ability to reorganise in childhood because its constantly adapting to new experiences and learning - but its been demonstrated that 40 hours of golf training produced changed in the neural representation of movement in p's ages 40-60 - shows that it does continue throughout the life span
• weakness - animal research 


  lots of research on plasticity and functional recovery uses animals - might not be able to generalise the results to human plasticity - humans have a much higher cognitive functions = plasticity could be different in animals and humans