Plasticity and Functional Recovery

Question 1

What is brain plasticity?

Answer 1

The brain’s ability to change and adapt (functionally and physically) as a result of or in reaction to the environment, experience and new learning.

Question 2

What is experience expectant plasticity?

Answer 2

The idea that changes in the brain take place during infancy and childhood.

Question 3

What is experience dependent plasticity?

Answer 3

The idea that the brain continues to create new neural pathways and alter existing ones as a result of learning and life experience

Question 4

What are the three ways plasticity can happen?

Answer 4

Synaptogenesis
Neurogenesis
Synaptic pruning

Question 5

What is synaptogenesis?

Answer 5

When new synapses are formed. This can occur throughout life but during infancy there is an explosion of Synaptic formation.

Question 6

What is Neurogenesis?

Answer 6

This refers to when neurons are grown. In infancy this is responsible for populating the growing brain with neurons but it also occurs in adulthood.

Question 7

What Synaptic pruning?

Answer 7

The process of synapse elimination that typically happens between early childhood and the onset of puberty
This has also been shown to occur to a lesser extent in adulthood.

Question 8

What has infancy shown about brain plasticity?

Answer 8

During infancy, the brain experiences a rapid growth in the number of Synaptic connections it has, peaking at approximately 15,000 by the age of 2-3. This is twice as many as there are in the adult brain. This shows that as we age, rarely used connections are deleted and frequently used connections are strengthened in a process known as cognitive pruning.

Question 9

Has does computer gaming show plasticity?

Answer 9

Kuhn illustrated the potential benefits of playing SuperMario for 2 months playing at least 30 minutes per day. They found significant increases in areas of the brain responsible for key behaviours such as working memory, planning and motor performance. Video games could be argued to have caused synaptogenesis.

Question 10

How has taxi drivers shown plasticity?

Answer 10

Maguire studied the brain’s of London taxi drivers using an MRI and found significantly more grey matter in the hippocampus than in a matched control group. Cabbies must take a complex test called the knowledge which assess their recall of city streets and possible routes. This is the part of the brain that is associated with the development of spatial and navigational skills. The longer they had the job, the more pronounced was the structural difference.

Question 11

How have astronauts shown plasticity?

Answer 11

Koppelmans studied the effect of no gravity in space and how this affects the brain. 27 astronauts were brain scanned before a space mission, then again upon their return. Between 2 weeks to 6 months in space, the cerebellum shrunk and the motor and somatosensory regions were swollen.

Question 12

What might happen to the brain following injury or other forms of trauma?

Answer 12

Individual may experience loss of brain function such as paralysis, aphasia etc. In these cases, unaffected areas sometimes adapt or compensate for those areas that are damaged. Functional recovery can happen quickly after trauma and then slows down after several weeks.

Question 13

What are the different types of functional recovery?

Answer 13

Neural regeneration
Neuronal unmasking
Neural reorganisation

Question 14

What is neural regeneration?

Answer 14

This is known as axon sprouting and it occurs when new nerve endings grow and connect with undamaged areas. This can compensate for damaged areas and enable the recovery of previously lost functions. This can be seen as a type of synaptogenesis

Question 15

What is Neuronal unmasking?

Answer 15

This occurs when dormant synapses in the brain are opened and become functional. This can occur when the surrounding brain area become damaged as the rate of input of these dormant synapses would increase opening connections of the brain that are not normally active and allowing the gradual development of new structures. This is a type of synaptogenesis or Neurogenesis

Question 16

What is neural reorganisation?

Answer 16

This occurs when the brain transfers functions from the damaged area to undamaged sections of the brain. In extreme cases whole areas of the brain me can take over the functions of damaged sections.

Question 17

Is there case study evidence to support plasticity?

Answer 17

Danelli investigated the case of an Italian boy who had most of his left hemisphere removed aged 2.5 to remove a tumour. With intensive therapy his right hemisphere was able to take over almost all of the functioning that would normally have been done by the left.

Question 18

Does the case study for functional recovery lack population validity?

Answer 18

Male Italian patient so the findings could be considered androcentric and does not represent people of different ages or cultures.

Question 19

Is there research into age for functional recovery?

Answer 19

Teubar found a negative correlation with age and recovery as when investigating soldier’s recovery from brain injury, 60% under 20 years made huge improvement whereas only 20% over 26 made similar improvement

Question 20

Is there refuting evidence for age and plasticity?

Answer 20

Boyke found even 60 year old could regain abilities thought to be fixed in childhood with intense retraining. Elbert concluded that capacity for neural reorganisation is much greater in children than in adults.

Question 21

Does research into plasticity have practical applications?

Answer 21

Stem cells planted into damaged areas of the brain have the potential to grow into neurons and make functional Synaptic connections. Tajiri found that stem cells provided to rats after trauma found a clear development of neuron like cells in the area of injury.