Plasticity and functional recovery after trauma Flashcards
(8 cards)
What is brain plasticity?
-The brain’s tendency to change and adapt as a result of learning and experience
-results in growth of new synaptic connections: Gopnik et al. (1999) 15,000 per neuron at age 2-3.
What is synaptic pruning?
-as we grow older, neural connections that arent used frequently are deleted and the ones that are used frequently are strengthened.
What was Bogdan Draganski’s et al. (2006) research into brain plasticity?
-imaged the brains of medical students 3 months before and after their final exams
-changes in posterior hippocampus and parietal cortex
Describe Maguire et al (2000) research into brain plasticity.
-studied the brains of london taxi drivers
-found significantly more grey matter in their posterior hippocampus(involved in development of spatial and navigational skills) compared to a matched control group
-Maguire found that the Knowledge test the drivers had to do altered this structure in their brain
-Positive correlation between number of years as a taxi driver and the amount of grey matter.
Evaluation of brain plasticity
L:- Negative plasticity: Medina et al (2007); brain’s adaption to prolonged drug use leads to increased chance of dementia and reduced cognitive abilities.
Also 60-80% of amputees experience phantom limb syndrome which is thought to be cortical re-organisation in somatosensory cortex as a result of limb loss (Ramachandran and Hirstein (1998)
S:-Age and plasticity: In general plasticity reduces with age but Ladina Bezzola et al (2012) demonstrated how 40 hours of golf training produces changes in the neural representatives of movement in participants aged 40-60. Using fMRI’s the researchers noticed increased motor cortex activity in the novice golfers compared to control group suggesting more efficient neural representations after training and neural plasticity throughout life.
However, small sample size 11 in both conditions and the people playing golf were likely rich as golf is expensive so may have done other enriching activities to give the change
What is functional recovery?
-A form of plasticity.
-Following damage through trauma, the brain’s ability to redistribute or transfer functions usually performed by a damaged area to other, undamaged areas
What happens in functional recovery?
-Axonal sprouting: the growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways
-Denervation supersensitivity: this occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost, however can lead to oversensitivity to messages of pain
-Recruitment of homologous (similar) areas on opposite side: this means specific tasks can still be performed e.g. Brocas area in left hemisphere damaged, the right hemisphere equivalent could carry out the functions
Evaluation of functional recovery.
-S:real world application: contributed to neurorehabilitation. Understanding of axonal growth permitted constraint-induced movement therapy to be used with stroke patients whereby the continue to practice to move their arm whilst their unaffected arm is restrained. Therefore, it helps doctors know when interventions need to be made
-L: cognitive reserve: level of education may affect functional recovery. Erich Schneider et al. (2014) revealed the more education a person with a brain injury (taken as an indication of cognitive reserve) the greater their chances of a disability free recovery (DFR) were. 40% of those with DFR had more than 16 years of education and thosr with 10% had 12 years.
S: Case study of gabby giffords: She was shot point blank in the head in 2011 and was placed in a coma by doctors. However, she was able to make a full recovery which shows brain plasticity.
