Lesson 9 - Plasticity & Functional Recovery Of The Brain After Trauma Flashcards
Plasticity
The ability of the brain to change and adapt synapses, pathways and structures in light of various experiences.
Positive Experiences That Cause Plasticity
Learning and memory, plasticity is more common for positive experiences.
Negative Experiences That Cause Plasticity
The ability of the brain to adapt to damage caused by trauma - it’s recovery of function lost due to brain damage which is called functional recovery.
Plasticity In A New Born
A baby’s brain has more neurons/synapses than a fully matured brain because it’s developing and continuously learning and experiencing new things.
Extreme Example Of Baby Brain Plasticity
If a baby born with a severely damaged hemisphere is removed after birth, the person as an adult shows very few impairments.
Plasticity Due To Life Experience
Researchers have studied to try and remove the effects of decreased cognitive functioning with age.
Plasticity Due To Life Experience Study
Boyle Et Al found brain plasticity in 60 year olds that were taught a new skill (juggling) had increased grey matter in their visual cortex but this stopped when they stopped juggling.
Plasticity With Meditation Study
Davidson Et Al compared 8 Tibetan meditators to 10 student volunteers, both groups were fitted with electrical sensors and asked to meditate, the monks had increased gamma waves whereas the students only had a slight increase in gamma waves.
Davidson Et Al Conclusion
Meditation makes permanent changes based on the monk’s gamma activity but also short term changes.
Plasticity Strengths
Animal Study Support
Human Study Support
Animal Study Support (+)
Kempermann Et Al found an increased amount of new neurons in rats in complexed environments, they also had increased neurons in the hippocampus.
Animal Study Support 2 (+)
Blakemore & Mitchell found visual neurons would permanently change in cats by being in a specific environment, kittens reared in an environment with vertical stripes didn’t respond to horizontal stripes showing how exposure affects brain development.
Human Study Support (+)
Maguire Et Al found London taxi drivers have a larger front part of the hippocampus which was positively correlated with how long they’d been driving taxis.
Plasticity Weaknesses
Can’t Be Generalised
Ethical Issues
Can’t Be Generalised (-)
Studies on animals can’t be generalised to humans and kittens were only exposed to one environment whereas babies aren’t.
Ethical Issues (-)
Consent and harm with babies.
Age Differences In Plasticity
Plasticised reduces with age but Bezzo Et Al showed 40 hours of golf training showed changes in 40-60 years, their motor cortex activity increased after the training.
Functional Recovery
The transfer of functions from a damaged area of the brain to an undamaged area.
Effects Of Traumatic Brain Damage
Can lead to paralysis, language problems and cognitive impairment. Blood supply is lateralised so damage is likely to be to a single hemisphere.
Hippocampus
Where new memories and the ability to navigate to different locations came from.
What Happens To The Brain During Recovery?
The brain rewires and reorganises by forming new synaptic connections. Secondary neural pathways that aren’t usually used are unmarked to enable normal functioning.
Functions Supporting Recovery
Axonal Sprouting
Denervation Supersensitivity
Recruitment To Homologous Areas
Axonal Sprouting
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways.
Denervation Supersensitivity
When axons that do similar jobs become aroused, to a higher level to compensate for lost ones, however it can make you oversensitive.
Recruitment Of Homologous Areas
Recruiting areas on the opposite side e.g. if the Broca’s area was damaged on the left, the right-sided equivalent would carry out it’s functions.
Homologous
Similar
Strengths Functional Recovery
Practical Applications
Age Differences In Recovery
Educational Attainment With Functional Recovery
Practical Applications (+)
Understanding functional recovery has helped with neurohabilitation which helps doctors provide therapy and electrical stimulation to speed up brain recovery.
Age Differences In Recovery (+)
Functional recovery reduces with age - Huttenlocher stated after childhood the only way to recover is to develop behavioural strategies however it’s shown that with retraining functional recovery can happen in adulthood.
Educational Attainment With Functional Recovery (+)
Schneider Et Al - patients with the equivalent of a college education are 7 times more likely to recover within a year fully, making cognitive reserve a factor in functional recovery, helping us encourage lutes to study.
