plasticity and functional recovery Flashcards
what is plasticity?
the ability of the brain to replace function lost by physical damage to the brain
what is functional recovery?
the ability of the brain to transfer functions from a damages area to an undamaged area
how does recovery work?
new branches of axons and dendrites must grow within neurons
(altho sometimes the brain adapts and finds another way to complete a function)
what are the three anatomical ways that a body can replace axon function?
-increased brain stimulation
-axon sprouting
-denervation supersensitivity
what is meant by ‘increased brain stimulation’?
damaged neurons effect neighbouring neurons since they no longer have an input (happens with hemispheres too)
altho damage is only on one side, the other hemisphere functions at a lower level also
what is meant by ‘axon sprouting’?
when an axon is damaged its connection with neighbouring neurons are lost
sometimes other axons that connect to that neuron will sprout extra connections, replacing the ones that were destroyed
-usually occurs 2 weeks after the damage
-only works if the damaged axon and compensatory axons do a similar job, otherwise it can cause problems
what is meant by ‘denervation supersensitivity’?
-axons that do a similar job become aroused to a higher level to compensate for the lost ones
-can have the consequence of hyper-sensitivity to messages like pain
what are the 4 factors affecting recovery of the brain after trauma?
-perseverance (sometimes lost functions may be because the individual isn’t trying)
-physical exhaustion, stress and alcohol consumption (doing a task takes much more effort)
-age (brain deteriorates when old, affects the extent and speed of recovery)
-gender (research suggests women recover better from brain injury as their function is not as lateralised)
Danelli et al 2013
-EB was operated on at 2 1/2 years old, brain tumour, most of his LH was removed, all linguistic abilities removed
-underwent intensive rehab, his language abilities started to improve at 5, continuing over the next 3 years, until there were little issues
-danelli found he had some minor grammar errors AT 17y/o
-RH had compensated but couldn’t do so entirely
schneider at al 2014
-769 people who had suffered brain injuries from road traffic incidents
-24% didn’t finish school
-51% had 12-15 years of education
-25% graduated uni
-one year after the injury, 28% had made a full recovery and were back in education/working
-39% of graduates were left free of disability
-those who left education early, only 10% made a recovery
-people who remained in education longer had greater ‘cognitive reserve’, meaning they were less likely to be left permanently disabled
-large sample shows general trends, but there are many other factors that could be involved
evaluate plasticity and functional recovery
-research has shown recovery is possible, evidence that rehabilitation programmes work
-some cases have no record of functioning prior to the damage, so its hard to know extent of recovery
-ability of the brain to recover depends on the extent of the damage, the location of it, and the person, so every case varies and generalisations are difficult
