Plasticity And Functional Recovery

Question 1

Plasticity

Answer 1

• describes the brains tendency to change and adapt as a result of experience and new learning, this generally involves a growth of new connections

Question 2

Plasticity facts

Answer 2

• has the ability to change throughout life
• during infancy the brain experiences rapid growth in the number of synaptic connections it has; 15,000 per neuron at 2-3 years old (synaptic pruning)
• twice as many in adult brain
• as we age, rarely used connections are deleted and frequently used connections are strengthened

Question 3

Maguire et. Al

Answer 3

• studied the brain of london taxi drivers
• found significantly more volume of grey matter in the posterior hippocampus than in a matched control group
• *associated with the development of spatial and navigation skills
• found that learning the knowledge altered the structure in taxi drivers brains, the longer they’d been in the job the more pronounced the structural difference was

Question 4

Draganski et al

Answer 4

• imaged the brains of medial students 3 months before and after final exams
• learning induced changes were seen to have occurred in the hippocampus and the parietal cortex presumably as a result of the exam

Question 5

Negative plasticity

Answer 5

• prolonged drug use has been shown to result in poorer cognitive functioning as well as an increased dementia later in life
• 60-80% of amputees have been known to develop phantom limb syndrome, these sensations are usually unpleasant, due to a cortical reorganisation of the somatosensory cortex as a result of the limb loss

Question 6

Hubel and Wiesel

Answer 6

• sewed one eye of a kitten shut and analysed the brains cortical response
• found that the visual cortex associated with the shut eye was no idle but continued to process infomation from the open eye

-> ETHICAL ISSUES

Question 7

Functional recovery after trauma

Answer 7

• following damage through trauma, functional recovery is the brains ability to redistribute or transfer functions usually performed by a damaged area to other un damaged areas

Question 8

Stage 1: axonal sprouting

Answer 8

• growth of nerve endings which connect with other undamaged never cells to form new pathways

Question 9

Stage 2: denervation supersensitivity

Answer 9

• axons that do a similar job become aroused to a higher level to compensate for lost ones

Question 10

Stage 3

Answer 10

• recruitment of homologous areas on opposite side of the brain, damage to Broca’s area would mean the right sided equivalent would carry out function

Question 11

Mechelli et al

Answer 11

• compared bilingual brains to matched monolingual controls
• found a larger parietal cortex in the brains of people who are bilingual