ways of studying the brain

Question 1

explain how fMRI works

Answer 1

works by detecting changes in blood oxygenation and flow that occur due to neural activity. When an area of the brain is more active it uses more oxygen and blood flow is directed there.
fMRI produces a 3D image showing which parts of the brain are active and must be therefore involved in particular mental processes.

Question 2

2 strengths of fMRI (risk-free, high spatial resolution)

Answer 2

one advantage is that it doesn’t use radiation, unlike a PET scan. It is virtually risk free and straightforward to use.
It also produces images that are high in spatial resolution, showing a great deal of detail by the milimeter and show a clear picture of localisation in the brain
This means an fMRI can safely provide a clear picture of how brain activity is localised

Question 3

weaknesses of fMRI (expensive, poor temporal resolution)

Answer 3

fMRI is expensive compared to other techniques and can only get a clear image if the person remains perfectly still.
It has poor temporal resolution because it has a 5 second lag between initial neural activity and image. It can be difficult to pinpoint when the activity occurs as there is a time lag

Question 4

EEG’s

Answer 4

measures electrical activity within the brain via electrodes using a skull cap. The scan recording represents the brainwave pattern of thousands of neurons. This shows overall brain activity.
EEG is often used as a diagnostic tool. For example unusual arrhythmic patterns of brain activity may indicate abnormalities such as epilepsy, tumours or sleep disorders.

Question 5

strength of ERPs

Answer 5

high temporal resolution

Question 6

weakness of ERPs

Answer 6

must eliminate all extraneous variables which is very hard to achieve.

Question 7

post mortem examination

Answer 7

a technique involving the analysis of a persons brain following their death
Areas of the brain are examined to establish their likely causes of a disorder that the person experienced in life.
May involve a comparison to a neurotypical brain to establish extent of the difference.

Question 8

strength of post mortem examinations

Answer 8

Post mortems used in locaisation and medical research. Broca and Wernicke both relied on post mortem examination studies. Used to link HM’s memory deficits to damage in his brain. This means they continue to provide useful information.

Question 9

weakness of post mortem examinations

Answer 9

Observed damage in the brain may not be linked to the defecits under review.
Post mortem studies raise ethical issues of consent after death eg HM
This challenges their usefulness in psychological research