Section 6 : Biopsychology - Plasticity

Question 1

What is plasticity

Answer 1

The ability for the brain to alter its structure and function in response to changes in its environment

Question 2

How does plasticity work

Answer 2

• info takes a pathway thru the brain, travelling from one neuron to another via synapses
• when we’re presented with new info, new neural pathways begin to form
• using a neural pathway strengthens it, the more a pathway is used, the stronger the connections between the neurons become
• if a neural pathway is not used it becomes weaker

Question 3

What is cortical representation

Answer 3

When different parts of the body are represented by the motor and somatosensory cortex’s. For example, one area in your somatosensory cortex processes sensory info from your lips and another area processes sensory info from your toes

Question 4

What is the method of Elbert et al 1995

Answer 4

• Nine musicians who played either violin, cello or guitar were compared to 6 non musicians
• a technique called magnetic source imaging was used to measure the area of the somatosensory cortex representing digits of the left hand of each participant

Question 5

What was the result of Elbert 1995

Answer 5

The area of the somatosensory cortex represented by the digits of the left hand was larger in the string instrument players than in the controls

Question 6

What was the conclusion of Elbert et al 1995

Answer 6

The findings suggest that the increased amount of sensory processing required from the left hands of the stringed instrument players results in structural changed in the brain, supporting plasticity

Question 7

What are the evaluations of Elbert et al 1995

Answer 7

• researchers argue that increased representation of the left hand digits in the musicians may have been genetic rather than as a result of playing an instrument
• small sample size not representative

Question 8

Karni et al 1995 provided support for motor cortex what did this study show

Answer 8

The study used fMRI to show that learning and practising a sequence of finger movements over a period of four week led to activation of larger area of the motor cortex when carrying out the sequence

Question 9

Nudo et al 1996 provided more support for plasticity in motor cortex. What did this study show

Answer 9

• Nudo et al mapped the motor cortex of adult monkeys before and after training in a task which mainly required use of the digits.
• they found that the representation of the digits in the motor cortex increased
• they then carried out training in a task mainly used in the forearm.
• they found that the forearm representation increased and the digit representation decreased.
• suggests that plastic changes are continuous and reversible (in monkeys)

Question 10

What are the advantages of using constraint-induced movement therapy (CIMT)

Answer 10

• numerous studies back CIMT and that it produces cortical reorganisation results in regained or improved function
• principles of CIMT can be applied to patients who suffer from aphasia as a result of stroke. Instead of communicating in other ways they play a game which requires them to try and speak a word presented on a card. Studies showed that this therapy caused dysfunctional areas near the damaged area to become functional again

Question 11

What are the disadvantages of CIMT

Answer 11

• CIMT can be very frustrating
• CIMT needs to be intensive to be effective
• most effective in treating patients who have suffered mild to moderate strokes. If there’s lots of damage to the brain, it can be much harder to regain function