brain: plasticity and functional recovery of the brain Flashcards
what did scientists initially believe about our brain?
Our brain was now fixed and our development phase was over once we reached adulthood.
Early researchers believed that you stopped creating new neurons shortly after you were born, this process is called neurogenesis.
what is neural plasticity?
It is believed that the human brain is able to adapt and change as a result of experience and learning throughout our lifetime.
what was Maguire’s method into her research of London black cab taxi drivers?
she obtained structural MRI scans of 16 right-handed male london taxi drivers. They had all been driving at least 1.5 years. Scans of 50 healthy right-handed males who did not drive taxis were included in comparison. The mean age did not differ between the two groups.
what were the results of Maguire’s method into her research of London black cab taxi drivers
increased grey matter was found in the brains of taxi drivers compared with controls in the two brain regions, the right and left hippocampus. The increased volume was found in the posterior hippocampus.
how do the findings of Maguire’s study support the idea of brain plasticity?
They found that there was a positive correlation between the longer the taxi drivers had been in the job, and the more pronounced was the structural difference.
What did Mechelli (2004) find out about the impact of speaking more than one language on our brain?
They found out that people who spoke more than one language had denser grey matter parietal cortex compared to those who only spoke one language.
This suggests that the structure of the human brain is altered by the experience of acquiring a second language.
What is meant by functional recovery?
This is the idea that following trauma or injury, the human brain can adapt as other unaffected areas may compensate for those that are damaged. Healthy parts of the brain may take over from damaged, destroyed or even missing areas.
what are the 3 ways that allow the brain to recover from trauma?
axonal sprouting
denerval supersensitivity
recruitment of homologous areas from other hemispheres
what is axonal sprouting?
New nerve endings grow and connect with nerve cells to form new pathways
what is denerval supersensitivity?
Axons that perform similar jobs become aroused to a higher level to compensate for the ones that are ‘lost’. This may also lead to oversensitivity of pain messages
what is Recruitment of homologous areas from other hemispheres?
Right sided equivalent carries out function until the left side is recovered. E.g. if Broca’s area was damaged on the left side of the brain, the right-side equivalent would carry out its functions.
AO3: how is ‘negative behavioural consequences’ a limitation to brain plasticity?
one limitation of plasticity is that it may have negative behavioural consequences. For example, evidence has shown that the brains adaption to prolonged drug use leads to poorer cognitive functioning in later life, as well as an increased risk of dementia. 60-80% of amputees have also been known to develop phantom limb syndrome, this is where they continue to experience sensations as though the limb is still there. These are usually very unpleasant and painful and are thought to be due to the cortical reorganisation in the somosensory cortex that occurs due to the result of a limb loss. Therefore, this suggests that the brains ability to adapt to damage is not always beneficial to the individual suffering due to the negative side effects.
AO3: how is ‘life long ability’ a strength to brain plasticity?
one strength to plasticity is that it may be a life-long ability. This suggests that in general plasticity reduces with age, however, Bezzola et al (2012) demonstrated how 40 hours of golf training produced changes in the neural representations of movement in participants aged 40-60. For example, researchers used fMRIs to observe increased motor cortex activity in the novice golfers compared to a control group, suggesting there was a more efficient neural representation after training. Therefore, this shows that our neural plasticity can continue through our lifespan. However, there is evidence that this can deteriorate with age as neural regeneration is less effective in older brains, explaining why adults may find change more demanding than younger people. This means that we should consider individual differences when assessing the likelyhood of functional recovery in the brain after trauma.
AO3: how is ‘real life application’ a strength to functional brain recovery?
one strength to functional recovery is that it has real life application. This is because by understanding the processes involved in plasticity, we have been able to make contributions to the field of neurorehabilitation. This means that by simply understanding that axonal growth is possible, we can encourage new therapies to be tried. For example, constraint-induced movement therapy is used with stroke patients whereby they repeatedly practice using the affected part of their body, such as their arm, whilst the other unaffected arm is restrained. This works by using motor therapy and electrical stimulation of the brain to counter the negative and deficits in motor and cognitive functions following accidents. This means that the research into functional recovery is useful as it helps medical professionals to know when interventions need to be made. Therefore, this has helped improve the cognitive functions of people suffering from injuries.
AO3: how is ‘levels of education’ a limitation to functional brain recovery?
one limitation to functional recovery is that someones education levels may influence their rate of recovery. For example, Eric Schneider et al (2014) revealed that the more time people with a brain injury had spent in education, the greater their chance of a disability-free recovery. This meant that their time spent in education was taken as an indication of their cognitive reserve, and they found that 40% of those who achieved a disability-free recovery had more than 16 years in education compared to about 10% of those who had less than 12 years in education. This implies that people with brain damage who have insufficient disability-free recovery are less likely to achieve a full recovery, and therefore, the positive effects of functional recovery vary from patient to patient.
