Biopsychology - Brain plasticity and functional recovery Flashcards
Define plasticity
The brain adapts in both its function and structure as a result of a change in the environment.
These changes could be due to damage, or to meet the cognitive demands of learning new skills.
name reasons for plasticity
Learning new skills
A result of developmental changes
Responses to direct trauma to areas of the brain
Response to indirect effects of damage such as swelling or bleeding (from stroke )
Define functional recovery
The functions that were performed by areas of the brain that are lost or damaged are performed by undamaged areas of the brain - functional reorganisation.
Define synaptic pruning
Synapses that are used frequently become stronger over time , however unused synaptic connections are lost, this makes the brain a more efficient communication system over time.
When is synaptic pruning highly active?
In the brains of newborns and children. You have more connections as an infant than you’ll ever have at any other time of your life
What is axonal sprouting?
The process of existing neurons growing new axons to connect to adjacent neurons. Neural regeneration is the growth of new neuronal cells.
What is denervation supersensitivity
To compensate for the loss of axons in a pathway the remaining axons become more sensitive (more likely to fire). This can result in side effects such as pain.
What factors affect functional recovery
Age: children have the best ability to recover, than young adults.
Sex: women are more able to recover from brain damage
Rehabilitative Therapy: Focused effort results in improvement
What is constraint induced therapy?
Stopping patients from using coping strategies (like body language for communication or using undamaged limbs for tasks) makes them improve via functional reorganisation
Strengths of plasticity?
+ Research support, Maguire et al. MRI brain scans of 16 male taxi drivers were compared to brain scans of 16 matched (age, gender) non taxi driver controls. The posterior hippocampi in the London taxi drivers were found significantly larger than the controls. Also, the size of the posterior hippocampi was positively correlated with the amount of time working as a taxi driver. Suggests physical structure of brain is plastic, can reconfigure itself to better adapt to psychological demands.
- Issues with correlational design
- Use of objective scientific measurements using MRI
+ Case study, EB. Age of two and a half EB had a hemispherectomy of the left side of his brain to remove a tumour. This removed language areas. Lost all language ability immediately. But after two years, language ability recovered. Even without his left hemisphere, EB developed normally as he aged apart from some dyslexia like symptoms. Researchers noted fMRI scans showed the right hemi followed a ‘‘left-like blueprint’’ for language. Suggests brain can adapt and recover after damage, especially early in life, with the right hemisphere taking roles usually performed by the left.
Strengths of plasticity and functional recovery
+ Research on brain plasticity and functional recovery has practical benefits. It has been useful in rehabilitative therapy, helping people return to their lives and productive, ultimately benefiting the wider economy
+ Research on individuals recovering lost function can help psychologists understand more about the functions of regions of the brain that were initially damaged.
Limitations of functional recovery
- There are limits to spontaneous and functional recovery. The brain can only ‘repair’ itself up to a specific point, after which motor therapy or electrical stimulation is needed to increase recovery rates. E.g Lieperta et al found that after constraint-induced movement therapy, the motor performance of stroke patients improved significantly. This suggests that functional recovery cannot be relied upon to reinstate normal function.
