plasticity and functional recovery

Question 1

What is plasticity?

Answer 1

-The brain’s tendency to change and adapt as a result of experience and new learning.
-This generally involves growth of new connections.

Question 2

What is functional recovery?

Answer 2

-a form of plasticity
-Following damage through trauma, the brains’ ability to redistribute or transfer functions usually performed by a damaged areas to other, undamaged areas.

Question 3

What is synaptic pruning?

Answer 3

-rarely used synaptic connections are deleted and frequently used ones are strengthened.
-Enables life-long plasticity where new neural connections are formed in response to new demands on the brain.

Question 4

True or False? Synaptic Pruning is an example of functional recovery and plasticity.

Answer 4

False. Synaptic Pruning is an example of plasticity only.

Question 5

What is axon sprouting?

Answer 5

-when an axon is damaged its connection with a neighboring neuron is lost.
-In some cases, other axons that already connect with that neuron will sprout extra connections to the neuron, replacing the ones that have been destroyed, compensating for the loss of a neighbor.

Question 6

How long after trauma can axon sprouting happen?

Answer 6

-This occurs for the most part 2 weeks after the damage happens

Question 7

What is Denervation Super Sensitivity?

Answer 7

-when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost

Question 8

What is recruitment of homologous areas?

Answer 8

-function moves to similar areas on the opposite side of the brain

Question 9

What was the aim of Maguire et al’s study?

Answer 9

-To examine whether structural changes could be detected in the brain of people with extensive experience of spatial navigation

Question 10

What was the procedure of Maguire et al’s study?

Answer 10

• Structural MRI scans were obtained.
  -16 right-handed male London taxi drivers that had all been driving for more than 1.5 years participated.
  -Scans of 50 healthy right-handed males that did not drive taxis were used as a control.
  -The mean age did not differ between the two groups.

Question 11

What were the findings of Maguire et al’s study?

Answer 11

-Increased grey matter was found in the brains of taxi drivers in the right and left hippocampi (compared with controls).
-The increased volume was found in the posterior hippocampus.
-A correlation was found between the amount of time spent as a taxi driver and volume in the right posterior hippocampus.

Question 12

What were the conclusions from Maguire et al’s study?

Answer 12

-Extensive practice with spatial navigation can cause structural changes to the brain, especially in the posterior hippocampus

Question 13

Who studied the ‘Italian Boy’ Case Study?

Answer 13

Danelli et al (2013)

Question 14

Who did Danelli’s research focus on?

Answer 14

-Followed EB, an Italian Boy that was operated on at the age of 2 ½ to remove a large benign tumor from his left hemisphere, resulting in him having virtually all of his left hemisphere removed.

Question 15

What was the initial impact of the surgery on Italian Boy?

Answer 15

-all of his linguistic abilities disappearing, as his language was seemingly localized in his left hemisphere, as he was right-handed

Question 16

What was the state of Italian Boy at age 5?

Answer 16

-his language abilities started to improve

Question 17

How was Italian Boy at age 17?

Answer 17

-his right hemisphere had compensated for the loss of the left hemisphere, and he was functioning linguistically well.
-When scanning EB’s brain, the brain activity was practically identical to the activity in ‘normal’ controls.

Question 18

What type of plasticity is EB an example of?

Answer 18

Recruitment of Homologous Areas

Question 19

What are the strengths of plasticity and functional recovery?

Answer 19

-research to support the idea of brain plasticity
-practical applications.

Question 20

What are the limitations of plasticity and functional recovery?

Answer 20

-negative plasticity

Question 21

Explain the strength of plasticity and functional recovery that there is research support?

Answer 21

-Kuhn et al found a significant increase in grey matter in various regions of the brain after participants played video games for 30 minutes over a two-month period.
-This is a strength because Kuhn provides clear evidence for brain plasticity and shows how experience (playing computer games) can cause structural changes in the brain.

Question 22

Explain the strength of plasticity and functional recovery that there are practical applications?

Answer 22

-application of findings to the field of neurorehabilitation
-Understanding the processes of plasticity and functional recovery has led to the development of neurorehabilitation which uses motor therapy and electrical stimulation of the brain to counter the negative effects and deficits in motor and cognitive functions following accidents, injuries and/or strokes.
-This matters because it demonstrates the positive application of research in this area to help improve the cognitive functions of people suffering from injuries.

Question 23

Explain the limitation of plasticity and functional recovery- negative plasticity?

Answer 23

-An issue with the brain’s ability to rewire itself is that it can lead to unintentional behavioral consequences, known as negative plasticity.
-For example, limb loss due to injury/trauma can trigger the continued experience of sensations in a missing limb as if it were still there.
-The development of this phantom limb syndrome produces sensations that are unpleasant and painful; thought to be due to cortical reorganization in the somatosensory cortex.
-This matters because it highlights the negative/ maladaptive consequences of functional recovery of the brain after trauma.

Question 24

Explain the limitation of plasticity and functional recovery that there are certain factors affecting recovery?

Answer 24

-Age, gender and level of education are all factors that affect recovery rates.
-plasticity reduces with age- Plata et al (2006) found that following brain trauma, 40+ year old patients regained less function in treatment than younger patients, and they were also more likely to decline it terms of function for the 5 years following the trauma.
-women recover better from brain injury than men, as women’s function is less lateralized, meaning that there will be some function on either side.
-Ratcliffe et al (2007) found that when assessed for cognitive skills, women performed significantly better than men on tests of attention/ working memory and language, whereas men outperformed females in visual analytic skills, overall results suggesting a better recovery for women.
-people with brain damage that have spent more time in education are more likely to achieve a full recovery
-Schneider et al (2014)n found that the more time people with a brain injury spent in education, (therefore the greater cognitive reserve), the greater their chances of a disability free recovery. 40% of those who achieved DFR had more than 16 years education compared to about 10% of those who had less than 12 years of education.
-This is a limitation because it puts certain demographics at a greater disadvantage in terms of likelihood of recovery, than others, for example an un-educated old man has much less chance of full recovery than a fully educated young woman.