ways of investigating the brain

Question 1

what are fMRI’s used for

Answer 1

to measure a persons brain activity whilst they perform a task (physical or mental)

Question 2

how do fMRI’s work

Answer 2

they detect changes in blood oxygenation
- parts of the brain that are more active have more oxygenated blood
- they produce 3d images showing which parts were involved

Question 3

strengths of fMRI’s

Answer 3

• doesn’t use radiation and is non-invasive so pretty much risk-free
• images have high spatial resolution, depicts detail by the milimeter

Question 4

weaknesses of fMRI’s

Answer 4

• very expensive
• images are only clear if they stay still
• poor temporal resolution, image has 5 sec delay time from initial firing
• only measures blood flow, difficult to say what kind of brain activity is being seen

Question 5

what are EEG’s used for (electroencephalogram)

Answer 5

used as a diagnostic tool to help diagnose and monitor brain conditions
- arrhythmic patterns of activity may indicate neurological abnormalities

Question 6

how do EEG’s work

Answer 6

• electrodes are fixed to a persons scalp using a skull cap
• they measure electrical activity within the brain
• scan recordings represent the brain wave patterns and provide an overall account of brain activity

Question 7

strengths of EEG’s

Answer 7

• invaluable in the diagnosis of conditions like epilepsy (random bursts of activity in the brain that are detected in screen easily)
• contributed to our understanding of sleep cycle
• high temporal resolution, 1 millisecond/ less

Question 8

weaknesses of EEG’s

Answer 8

• generalised information received
• not useful for pinpointing the exact source of neural activity
• doesn’t distinguish between activities originating in diff but adjacent areas

Question 9

What is an ERP

Answer 9

types of brain waves that are triggered by particular events
- research has revealed many different forms of ERP and how they are linked to cognitive processes

Question 10

what are ERP’s used for (event-related potentials)

Answer 10

to study how the brain responds to specific stimuli or tasks, like attention, perception, decision making

Question 11

How do ERP’s work

Answer 11

• isolate neuronal responses associated w specific sensory, cognitive, motor events
• filter out all extraneous brain activity from the original EEG recording using a statistical averaging technique

Question 12

Strengths of ERP’s

Answer 12

• Bring more specificity to the measurements of neural processes that could never be achieved using raw EEG data
• Excellent temporal resolution,, which has led to widespread use in the measurement of cognitive functions and deficits
• Many types have been discovered and precise roles in cognitive functioning can be described

Question 13

Example of a type of ERP

Answer 13

P300 component thought to be involved in the allocation of attentional resources and the maintenance of working memory

Question 14

Weaknesses of ERPS

Answer 14

Lack of standardisation in erp methodology between different research studies so difficult to confirm findings
- To establish pure data background noise and extraneous materials must be completely eliminated which is not easy to achieve

Question 15

What are post-mortem examinations used for

Answer 15

To see the effects of rare disorders and unusual deficits in mental processes on the brain

Question 16

How do you post mortems work

Answer 16

• Analysis of a person’s brain following their death
• Areas of damage within the brain are examined as a means of establishing the likely cause of the affliction the person experienced
• Could involve comparison with a neurotypical brain to see the extent of the difference

Question 17

Strengths of post mortems

Answer 17

• Vital in providing a foundation for early understanding of key processes in the brain
• Improve medical knowledge and help generate hypotheses for further studies

Question 18

Example of post-mortems in early understanding

Answer 18

Broca and Wernicke relied on post-mortem studies to establish links between language, brain and behaviour

Question 19

Weaknesses of postmortems

Answer 19

• Causation is an issue, damage may not be linked to the deficit but to some other unrelated trauma or decay
• Ethical issues of consent from individuals before death, may not be able to provide informed consent

Question 20

Example of ethical issues in post mortems

Answer 20

H M lost his ability to form memories so was not able to provide such consent
- but post mortem research was conducted on his brain regardless of this