plasticity and functional recovery after trauma

Brain plasticity

Ability of the brain to change and adapt synapses, pathways and structures in light of various experiences

Can also involve the ability of the brain to adapt to damages caused by trauma

Synaptogenesis

Where new synapses are formed this can occur throughout life but during infancy there’s an explosion of synaptic information

Neurogenesis

new neurons are grown

In infancy this is responsible for populating the growing brain with neurons but also occurs in adulthood

Synaptic pruning

Process of synapse elimination that typically happens between early childhood and onset of puberty

Also shown to occur to a lesser extent of adulthood

Experience expectant plasticity

Infancy: brain experiences rapid growth in the number of synaptic connections it has, peaking at 2-3 years (Twice as many as in adult brain)

Conclusions: existing neural connections can change/ new neural connections can be formed as a result of learning and experience

Experience dependent plasticity

Brain continues to create new neural pathways and alter existing ones as a result of learning and life experiences

Computer gaming

Kuhnet et al (2014) illustrated the potential benefits of playing super Mario 30 mins a day for 2 months

Found increases in areas of the brain responsible for key behaviors such as working memory, planning and motor performance

Conclusions: video games can be argued to have caused synaptic changes because more grey matter developed in the area

Taxi driving

Maquire et al (2000) studied the brain of London cab drivers and found they have significantly higher grey matter in the posterior hippocampus then the control group

Area associated with navigational skills due to ‘the knowledge’ test of routes and London streets

Conclusions: longer they had been doing the job the more pronounced the structural differences in the hippocampus

Astronauts

Koppelmans (2017) looked at how no gravity affects the brain, 27 astronauts scanned before their space mission then again on return

found that between 2 weeks and 6 months in space their cerebellum shrunk (involved in coordination) which positively correlated with how much time spent in space and motor somatosensory regions swelled

conclusions: means that upon return their brain returned to normal, demonstrating brains plasticity

Functional recovery

occurs following physical injury to the brain like trauma leading to paralysis, aphasia or memory loss

unaffected areas are able to adapt and compensate for damaged areas

an example of neural plasticity

Neural regeneration

also known as axon sprouting and occurs when new nerve endings grow and connect to damaged areas

can compensate for damaged areas and recovers lost functioning

can be seen as a type of synaptogenesis

Neural unmasking

Occurs when dormant synapses in the brain that exist anatomically but are blocked from functioning are opened and become functional

occurs when surrounding area becomes damaged as the input to these dormant synapses would increase, opening connections to regions of the brain normally activated and allowing the gradual development of lost structures

seen as a type of synaptogenesis

Neural reorganisation

Occurs when brain transfers functions from the damaged areas to undamaged sections of the brain

If Broca’s area in the left hemisphere was damaged then an area on the right hemisphere might take over

in extreme cases and with extensive therapy whole areas of the brain can take over the functions of damaged sections

Supporting research: Danelli (2013)

Danelli investigated a case of an italian boy (EB) who had most of his left hemisphere removed aged 2 ½ to remove a tumour

with intensive therapy his right hemisphere was able to take over its functioning, language and speech, that would have normally been done by the left

Strength: research support

there’s research to support the idea that the rain can recover, at least to some extent, from physical trauma

Danelli (2013)- small italian boy who had most of his left hemisphere removed at 2 ½ years due to a brain tumour.

with intensive therapy his right hemisphere was able to take over almost all of the functioning (language speech etc) that would normally have been done on the left, EB’s brain showed maximal plasticity.

Implies the brain is more capable for reorganising itself and supports the idea of plasticity

Weakness: Case study

This research is a case study and therefore lacks population validity

this study only relates to men (andocentric) and italians (ethnocentric) this means we do not know the affects it will have on a woman, someone older or in another country

Implies that support for plasticity lacks credibility, casting doubt on plasticity of the brain.

strength: practical applications

Research will inevitably lead to very useful practical applications

Newer research into the role of stem cells implanted in a damaged area have the potential to grow into neurons and make functional synaptic connections that would help restore behavioural functions.

Tajiri et al (2013) has shown the potential of this with rats with traumatic brain injuries

Research is in its early days so there is a long way to go yet but its an exiting avenue to explore

Weakness: theoretical flaws

recovery from brain trauma is not universal and there are a number of factors that may influence an individuals ability to recover

one identified factor is age, with most research indicating that functional plasticity reduces with age

Teubar (1975) found a negative correlation with age and recovery when investigating soldiers recovering from brain injury 60% under 20 years and 20% after 25 years

this could mean that plasticity of the brain is clearly affected by age