Plasticity and functional recovery

Question 1

plasticity of the brain

Answer 1

The ability of the brain to change and adapt synapses, pathways and structures in light of various experiences

Question 2

When is the best time to study plasticity?

Answer 2

The first year of a babies life

Question 3

Why is the first year of a babies life the best time to study brain plasticity?

Answer 3

Because it has more neurons and synapses than it will when it becomes fully mature in late adolescence

Question 4

Boyke et al (2008)

Answer 4

Found evidence for brain plasticity in 60 year olds taught a new skill - juggling. An increase in grey matter in the visual cortex resulted, although the changes were reversed when practising stopped.

Question 5

What can cause brain plasticity?

Answer 5

New born babies, life experience and meditation

Question 6

Davidson et al (2004)

Answer 6

Compared eight practitioners of Tibetan meditation with 10 student volunteers with no meditation experience. Both groups had electrical sensors and greater activation of gamma waves was shown

Question 7

What are the strengths of plasticity?

Answer 7

• Research support from animal studies
• Research support from human studies
• Age differences

Question 8

What is the research support from animal studies for plasticity?

Answer 8

Kempermann et al (1998)
Blakemore and Mitchell (1973)

Question 9

Kempermann et al (1998)

Answer 9

Found that rats housed in complex environments had more neurons than those in a control group housed in bare lab cages, particularly in their hippocampus

Question 10

Blakemore and Mitchell (1973)

Answer 10

Development of visual cortex in cats, characteristics of visual neurons were permanently changed by exposure to specific environments after birth. Kittens reared in environment with black vertical stripes didn’t respond to horizontal ones

Question 11

What is the research support from human studies for plasticity?

Answer 11

Maguire et al (2000)

Question 12

Maguire et al (2000)

Answer 12

Studied London taxi drivers to discover whether changes in the brain could be detected as a result of their extensive navigational experience. Used an MRI and calculated grey matter compared to control. Front part of hippocampus larger than controls

Question 13

What are the age differences in plasticity?

Answer 13

It reduces with age and has greater propensity for reorganisation in childhood but it can occur in older people.

Question 14

Who studied age differences in plasticity?

Answer 14

Bezzola et al (2012)

Question 15

Bezzola et al (2012)

Answer 15

demonstrated how 40 hrs of golf training produced changes in neural representations of movement in ppts aged 40-60
used FMRI found reduced motor cortex activity before training but after it increased, shows plasticity in older people

Question 16

What are the weaknesses of plasticity?

Answer 16

• Negative plasticity
• Generalisation issues with animals
• Ethical issues with animals

Question 17

Negative plasticity

Answer 17

A limitation of plasticity as it may have negative behavioural consequences and adaptation to prolonged drug use leads to poorer cognitive functioning in later life and increased risk of dementia, (Medina et al 2007)

Question 18

Medina et al (2007)

Answer 18

prolonged drug use leads to a lack of connections and risk of dementia

Question 19

What issues with generalisation is there when studying animals in plasticity?

Answer 19

Both kittens and rats are completely different to humans, rats and kittens are mobile from birth so brain development is faster than humans

Question 20

What are the ethical issues with animals in studying plasticity?

Answer 20

studies carried on rats and kittens are ethically questionable (Blakemore and Mitchell only exposing kittens to verticals stripes

Question 21

Functional recovery

Answer 21

transfer of functions from a damaged area of the brain after trauma to other un damaged areas

Question 22

what are common types of brain trauma?

Answer 22

Physical trauma
Cerebral haemorrhage
Cerebral ischaemia

Question 23

Cerebral haemorrhage

Answer 23

(stroke) when blood vessel in the brain bursts and brain areas start to die and the pressure of the blood can damage brain tissue

Question 24

Cerebral ischaemia

Answer 24

(stroke) blood vessel in the brain is blocked by a blood clot (thrombosis) or the thickening of blood vessel walls through fatty deposits (arteriosclerosis) brain areas die

Question 25

Aphasia

Answer 25

impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

Question 26

amnesia

Answer 26

loss of memory

Question 27

What can a traumatic brain injury cause?

Answer 27

Damage to all areas of behaviour and cognition. Movement paralysis, language problems, memory problems or difficulties in perception

Question 28

What happens to the brain naturally during recovery?

Answer 28

It can retire and reorganise itself by forming new synaptic connections close to the area of damage (Doige 2007)

Question 29

What are the of structural changes in the brain that take place during recovery?

Answer 29

Axonal sprouting

Question 30

Denervation supersensitivity

Question 31

Recruitment of homologous areas

Question 32

Neuronal unmasking

Question 33

Axonal sprouting

Answer 33

The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

Question 34

denervation supersensitivity

Answer 34

Axons that do a similar job become aroused to a higher level to compensate for the ones that are lost. can cause over sensitivity to pain

Question 35

Recruitment of homologous areas

Answer 35

Areas on the opposite side of the brain perform specific tasks

Question 36

Neuronal unmasking

Answer 36

Wall (1977) identified dormant synapses, synaptic connections that exist anatomically, but have a blocked function

Question 37

What ground breaking study supported the process of functional recovery after brain trauma?

Answer 37

Danelli et al (2013)

Question 38

Who did Danelli et al (2013) study?

Answer 38

An Italian boy named EB who had an operation at the age of 2.5 years to remove a benign tumour from his left hemisphere. After the operation, EB lost all his linguistic abilities. he was right handed so language located in the left hemisphere

Question 39

How did Danelli et al (2013) study EB?

Answer 39

He has lost all language abilities (located in left hemisphere) and he underwent an intensive rehabilitation programme and his language abilities started to improve at age 5. They continued to do so over the next three years to the point when he no longer had any language difficulties.

Question 40

What did Danelli et al (2013) find in EB after rehabilitation?

Answer 40

At age 17, compared to 'normal' controls, they found that his right hemisphere had compensated for the loss of the left hemisphere and that his linguistic abilities were functioning well! This study supports the idea of functional recovery in the recruitment of homologous areas

Question 41

What is the evaluation of functional recovery after trauma?

Answer 41

+- Practical application

Question 42

- Educational attainment

Question 43

- Gender differences

Question 44

- Age differences

Question 45

What are the practical applications of functional recovery?

Answer 45

+ Has contributed to neuro-rehabilitation

Question 46

- Uses therapy and electrical stimulation of the brain to counter the deficits in motor or cognitive functioning. may fix itself to a point but needs intervention to be success

Question 47

What are the age differences in functional recovery?

Answer 47

- Functional recovery after brain trauma reduces with age (Huttonlocher, 2002)

Question 48

- Only option beyond childhood is to develop compensatory behavioural strategies

Question 49

- Elbert et al (2001)

Question 50

Elbert et al (2001)

Answer 50

Concluded that the capacity for neural reorganisation is much greater in children than adults as shown by the extended practice that adults require in order to produce changes

Question 51

Educational attainment in functional recovery

Answer 51

Research suggests that education has an effect on functional recovery. Schneider et al (2014)

Question 52

Schneider et al (2014)

Answer 52

Patients with the equivalent of a college education are 7x more likely to recover and be disability free a year after brain trauma compared to those not finishing high school education.

Question 53

What did researchers conclude from Schneider et al (2014) study?

Answer 53

'cognitive reserve' (associated with greater educational attainment) could be a factor in neural adaptation during recovery after traumatic brain injury - in other words the longer the time spent in education had a direct relationship with functional recovery after trauma.

Question 54

Gender differences in functional recovery

Answer 54

research to suggest that women recover better from brain injury as their function is not as lateralised as men. Ratcliffe et al (2007)

Question 55

Ratcliffe et al (2007)

Answer 55

examined 325 patients with brain trauma response for cognitive skills to rehabilitation. They were 16-45 years old at injury, received rehabilitation at a care facility, and completed a follow-up one year later.

Question 56

What was found in Ratcliffe et al (2007)?

Answer 56

Women performed better than men on tests of attention/working memory and language. Men outperformed females in visual analytical skills. Overall, the results suggested a better recovery for women

Question 57

What may have influenced the results of Ratcliffe et al (2007)?

Answer 57

Results did not control for performance pre-injury.