Brain plasticity and functional recovery Flashcards
Explain what is meant by plasticity in the brain?
Plasticity is the brains tendency to change and adapt as a result of experience and new learning. This involves the growth of new neural connections.
What is Synaptic pruning?
The process in which the brain removed unused synaptic connections,and this strengthens the more frequently used synapses, making the brain a more efficient communication system.
What is Axonal sprouting?
When existing neurons grow new nerve endings (axons) to connect to adjacent undamaged neurons to form new neuronal pathways.
What is Denervation supersensitivity?
Axons which have a similar job compensate for lost axons by becoming aroused to a high level. ( more senstive = more likely to fire )
Side effects such as pain
What is meant by ‘ Recruitment of homologous areas on the opposite side of the brain’ ?
This is when the opposite side of the brain rectruits roles of the other. E.g if the brocas area was damaged the RH equivalent would carry out its functions. After a period of time the functionality may then return to the LH.
What are the factors affecting functional recovery?
Age - Children have the best ability to recover
Gender - Women are more able to recover
Rehabilitative therapy - therapy results in imporvement
What is functional recovery?
A form of plasticity.
Following damage through trauma, the brains ability to redistribute or transfer functions usually perfomed by a damaged area to a undamaged area.
Plasticity
Research Evaluation : Maguire (2000)
- Studied the brains of taxi drivers and found significantly more volume in the grey matter in the prosterior hippocampus than in the control group.
- This part of the brain is concerned with memory and navigation skills.An important part of being a taxi driver in London is knowing the city in great detail.
- Maguire found that there was a positive correlation with the size of the hippocampus and the time working as a taxi driver.
- This supports the theory of brain plasticity as it suggests the brain can reconfigure itself to better adapt to psychological demands.
Plasticity
Research Evaluation : Draganski (2006)
-Looked at medical students 3 months before and after their final exams.
-There were changes to the posterior hippocampus and parietal cortex.
-This is presumed to have been caused by learning.
-This also supports plasticity as it suggests the brain can modify structure to meet demands.
Functional recovery
Research Evaluation : Danelli (2013)
- At age 2 patient EB had a hemispherectomy of the left side of is brain to remove a tumour.
- This removed the language centres of Brocas and Wernickes areas.
- Immediately after surgery EB had lost all language ability (aphasia) . However after 2 years of recovery EB had recovered his language ability. Even without his LH EB developed normally as he aged asides from dsylexia like symptoms.
- This research suggets that the brain can adapt and recover after significant damage, especially in early life with undamaged areas taking responsibilty of damaged areas.
Evaluation 1 : Negative behavioural consequences of plasticity
- Evidence has shown that the brains adaptation to prolonged drug use leads to poorer cognitive functionining in later life, as well as an increased risk of dementia (Medina 2007).
- Also 60-80% of patients also develop phantom limb syndrome - the experience of sensation in the missing limb as if was still there.
- Hirstein 1998 found these sensations to be painful and thought to be due to the cortical reorganisation in the somatosensory cortex.
- This suggests the brains ability to adapt to damage is not always benificial.
Who found plasticity and prolonged drug use impairs congitive ability?
Medina 2007
Who found that the phantom limb syndrome is due to cortical reoganisation ?
Hirstein 1998
Evaluation 2 : Plasticity does not always decline with age
- Plasticity reduces with age, but Bezzola (2012) demonstrated how 40 hours of golf training produced changes in the nerual represenatation of movement in participants aged 40-60.
- Using FMRI the researchers observed increased motor cortex activity in the novice golfers compared to a control group.
- Suggesting more efficient nerual represenation after training, showing that plasticity can continue through a lifespan.
Who found that plasticity can continue through a lifespan?
Bezzola (2012)
Functional Recovery
Evaluation 1 : research into real world application
- Understanding the process involved in plasticity contributed in the field of neurorehabilitation.
- Constraint induced movement therapy is used with stroke patients whereby they repeatedly practice using the affected part of their body, while the unaffacted arm is restrained.
- This shows that research into functional recovery is useful as it helps medical professionals know when interventions need to be made.
Functional Recovery
Evaluation 2 : level of education may influence recovery rates.
- Scneider (2014) revealed that the more time people with brain injury spent in education - the greater chances of Disability free recovery.
- 40% of those who achieved DFR had more than 16 years of education comapred to those with 10% to those who had 12 years of education.
- This implies that some individuals have a greater cognitive reseve aiding in recovery.
Who found that there are individual differences in recovery rates?
Schneider (2014)
