Brain research and plasticity.

Question 1

What are fMRIs?

Answer 1

• uses blood flow of brain to indicate level of activity, because more blood means more oxygen going to the brain.
• head placed in large electromagnet
• Produces 3D images.

Question 2

Advantages of fMRIs?

Answer 2

-Does not use radiation so is usually risk free.
-Images have high resolution so clear activity.

Question 3

Disadvantages of fMRIs?

Answer 3

-Expensive.
-Has a 5 second time lag.
-Have to lie completely still to get clear image.
-Only shows blood flow, so may ignore inter connectivity.

Question 4

What are EEGs?

Answer 4

-A test used to find problems related to electrical activity of the brain. An EEG tracks and records brain wave patterns.
-Electrodes are placed on the scalp, attached to a skull cap.
-The scans represent brainwave patterns.

Question 5

Advantages of EEGs?

Answer 5

-High temporal resolution so there is no time lag.
-Non-invasive and not uncomfortable.
-Cheaper than fMRIs.

Question 6

Disadvantages of EEGs?

Answer 6

-Only a general idea of brain acitivity, you cannot pinpoint the location.

Question 7

What are ERPs?

Answer 7

An event-related potential (ERP) is the measured brain response that is the direct result of a specific sensory, cognitive, or motor event.
-Small voltage changes are detected.

Question 8

Advantages of ERPs?

Answer 8

high temporal resolution
information can also be gained from the spatial distribution of the scalp recordings
provide a dynamic picture of brain activity over time

Question 9

Disadvantages of ERPs?

Answer 9

-Only in the outer layers.
-Extraneous variables must be eliminated,
-Lack of standardisation between different research studies.

Question 10

What are post moretem examination?

Answer 10

The brain is analysed after death to determine whether certain observed behaviours during the patient’s lifetime can be linked to abnormalities in the brain.
-Compare with neurotypical brains.

Question 11

Advantages of PMEs?

Answer 11

-Vital in providing understanding before fMRIs and EEGs.
-Detailed examinations and deep exploration of tissue

Question 12

Disadvantages of PMEs?

Answer 12

-Issue of causation, the structure abnormality and the patient may not be linked.
-No informed consent.

Question 13

What is brain plasticity?

Answer 13

the brain’s ability to change structure and function as a result of experiencePl

Question 14

Plasticity throughout life?

Answer 14

-When 2-3 years old, 15000 synaptic connections per neuron, because of rapid learning and growth. This decreases with age.

Question 15

What is synaptic pruning?

Answer 15

as we grow older, weak neural connections are broken while strong ones are bolstered, increasing the efficiency of our brains.

Question 16

Maguire et al aim?

Answer 16

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

Question 17

Maguire et al method?

Answer 17

-Obtained 16 MRIs form right handed male taxi drivers in London, and 50 MRIs from normal right handed males.
-Same mean age and all drivers had been driving for more than a year and a half.

Question 18

Maguire et al findings?

Answer 18

-Increase in grey matter of the right and left hippocampus in the taxi drivers compared to the control group.
-A correlation was found between how long they had been driving and the volume of the hippocampus.

Question 19

Maguire et al evaluation?

Answer 19

-Had mundane realism. MRIs are objective and scientific.
-Small sample and only male.

Question 20

Davidson et al method?

Answer 20

-Compared 8 practitioners of Tibetan meditation with 10 students.
-Both were fitted with electrical sensors and were asked to meditate.

Question 21

Davidson et al findings?

Answer 21

-Much greater increase in gamma waves in monks.
-They also has more to begin with.
-This demonstrated long and short term change.

Question 22

What is functional recovery?

Answer 22

A form of plasticity. Following damage through trauma, the brain’s ability to redistribute or transfer functions usually performed by a damaged area(s) to other, undamaged area(s).

Question 23

Functional recovery over time?

Answer 23

Quicker in immediate weeks, then slows and you need rehabilitation.

Question 24

What is axonal sprouting?

Answer 24

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

Question 25

What is blood vessel reform?

Answer 25

Repairs need oxygen and glucose to blood vessels reform to supply this.

Question 26

What is recruitment of homologous areas?

Answer 26

Regions on opposite sides of the brain take on functions of damaged areas. Functionality may return over time.

Question 27

Tajairi et al?

Answer 27

2013. found that stem cells provided to rats after brain trauma showed a clear development of neuron-like cells in the area of injury. This demonstrates the ability of the brain to create new connections using neurons manufactured by stem cells

Question 28

Strengths of functional recovery?

Answer 28

-Practical application. Improving techniques for rehab and recovery after a stroke or brain surgery.
-Is a lifelong ability, although it does reduce with age.
-Support from animal studies (Hubel and Wiesel sewed a kitten’s eye closed, still processed information from the open eye).

Question 29

Weaknesses of functional recovery?

Answer 29

60-80% of amputees experience phantom limb syndrome. They have sensations as if the limb is still there. They are painful and uncomfortable. They are thought to be caused by the reorganisation of the somatosensory cortex.