Ways of studying the brain

Question 1

What are the 4 brain scanning techniques?

Answer 1

FMRI
EEG
ERP
Post Mortem

Question 2

Outline FMRI as a brain scanning technique.

Answer 2

FMRI (Functional magnetic resonance imaging) works by detecting the changes in both blood flow and oxygenation that occur as a result of brain activity in specific parts of the brain.

• Areas which are richer in oxygen are more active.

Question 3

Outline EEG as brain scanning techniques.

Answer 3

EEGs measure electrical activity within the brain via electrodes that are fixed to an individuals scalp using a skull cap.

• The scan represents brain wave patterns that are generated from the action of thousands of neurons, provididng a overall account for all brain activity.

Question 4

What are EEGs most used for?

Answer 4

They are used as a diagnostic tool to analysis arythmic patterns to identify neuroilogical abnormalities such as sleep disoreder , epilepsy or tumours.

Question 5

Outline ERPS as brain scanning techniques.

Answer 5

ERPs use the same scanning techiques as EEGs, however they isolate the motor,sensory and cogitive responses using a statistical averaging technique which combines all the data recorded from the presentation of the specific stimulus, and removes any extreneous brain activity from the original EEG.

-This leaves ERPs which are specific brainwaves triggered by particular events.

Question 6

Outline Post Mortem as a form of brain scanning techniques.

Answer 6

This is when the brain is precisely analysed after death to determine whether certain observed behaviors during the persons lifetime can be linked to structrual abnormalities in the brain.

-Often happens with rare disorders and/or unusual deficits in mental processes or behaviour during a lifetime.

Question 7

Strength of FMRI : It does not rely on the use of radiation.

Answer 7

• Unlike the use of PET scans, fMRI does not rely on radiation.
• If administered correctly it is virtually risk free , non-invasive and straight forward to use.
• It also produces images which have very high spatial resolution, depicting detail by the mm, and providing a clear picture of how the brain is actively localised.
• This means fMRI can safely provide a clear picture of brain activity.

Question 8

One limitation of FMRI : Expensive compared to other imaging techniques.

Answer 8

• It has poor temporal resolution because there is around 5 seconds time lag behind the image on the screen and the initial firing of neuronal activity.
• This means fMRI may not truly represent moment to moment brain activity.

Question 9

One strength of EEG : Has been useful in studying the stages of sleep and medical diagnosis.

Answer 9

• By detecting random bursts of activity in the braain, it has been able to help diagnose epilepsy.
• Unlike FMRI, EEG has high temporal resolution. EEGs can accurately detect brain activity at a resolution of a single milisecond.
• Also cheaper than FMRI, and the participant can move.
• Showing real world application of the technique.

Question 10

One limitation of EEGS : Poor spatial resolution.

Answer 10

• As EEGs pattern is a large sum of neurons in the cortex, it makes it difficult to pinpoint the exact source of neural activity.
• Therefore it does not allow researcher to distinguish between activities originating in different but adjacent locations.

Question 11

One strength of ERPs : Excellent temporal resolution.