L8 - Plasticity And Functional Recovery

Question 1

What is Brain Plasticity?

Answer 1

• The brains ability to change and adapt as a result of experience.
• Plasticity allows the brain to cope better with indirect effects of brain damage e.g stroke or swelling/haemorrhage

Question 2

Types of Plasticity

Answer 2

LIFE EXPERIENCE

• Frequently used nerve pathways develop stringer connection, and rarely used ones die
• By developing new connections and reducing weak ones, the brain can adapt to a changing env
• There is a decline in cognitive functioning with age because of these changes, e.g a person taught 60 year olds a new skill and found increased grey matter in the visual cortex

VIDEO GAMES

• Psychologist compared a control group to a group who had been video game training for 30 mins a day for two months on Super Mario.
• Playing video games increased the grey matter in the visual cortex, hippocampus and cerebellum.
• Results in new synaptic connections in brain areas involved in spatial nav, strategic planning, working memory and motor performance.

MEDITATION

• A psychologist compared 8 practitioners of Tibetan meditation with 10 students with no experience.
• An EEG picked up greater gamma wave activity in the monks before they started meditating
• Gamma waves coordinate neural activity

Question 3

Evaluation of Plasticity (+)

Answer 3

+ A psychologist found more new neurons in the brains of rats in complex env compared to those in lab cages. The increase in neurons was most prominent in the hippocampus, involved in forming new long term memories and navigation

• Another psychologist measured grey matter in the brains of London Taxi drivers using an MRI scan. The hippocampus in taxi drivers was significantly larger than a control group and this was positively correlated with the amount of time they had been a taxi driver.

Question 4

What is Functional Recovery

Answer 4

• Form of plasticity
• After damage, the brain transfers functions performed by damaged areas to undamaged areas.
  When the brain is still maturing, recovery is more likely, however the brain is capable of functional recovery/ plasticity at any age.
  Women recover better than men
• Spontaneous recovery from a brain injury slows after a number of weeks so physiotherapist is required to maintain improvements in functioning. So,e techniques are movement therapy and electrical stimulation to counter deficits in motor and cognitive functioning

Question 5

What is Neural Reorganisation, Neural Regeneration and Axon Sprouting?

Answer 5

Neural Reorganisation - Transfer of functions from damaged to undamaged areas

Neural Regeneration - Growth of new neurons or connections to compensate for damaged areas

Axon Sprouting - Part of Neural Regeneration. New nerve endings grow and connect with undamaged nerve cells to form new neural pathways

Question 6

Evaluation of Functional Recovery (+/-)

Answer 6

+ Phantom Limp Syndrome can be used as evidence of neural reorganisation. It is the continued experience of sensation in the missing limb. It is often painful/unpleasant. Caused by neural reorganisation in the somatosensory cortex

+ A psychologist sewed one eye of a kitten shut and analysed the the brains cortical response. The visual cortex for the shut eye was not idle and it continued to process info from the open eye. The brain areas can reorganise themselves and adapt their functions

• A psychologist found that patients with a college education are 7x more likely to be disability free a year after moderate/severe brain injury than those who did not finish secondary school. This meant neural reserve could be a factor in recovery