Fmri’s

Question 1

What do fMRI;s allow us to observe?

Answer 1

Observe and measure brain function

Question 2

What can we see with FMRI’s?

Answer 2

See the areas that are currently active, not only the structure

Question 3

How do FMRI’s work?

Answer 3

Work by detecting blood oxygenation to each area of the brain (more active areas require more oxygen)- called the BOLD signal- blood oxygenation level dependent signal
They use large magnets to detect oxygenated haemoglobin blood flow

Question 4

Weaknesses of fmri’s- temporal resolution?

Answer 4

Low temporal resolution

Question 5

Weakness- cost?

Answer 5

Expensive due to the highly technical, specialist equipment and highly skilled personnel involved
Limited to countries, regions/institutions that can afford to purchase and maintain the scanners in the first place
Sample sizes in FMRI research tend to be small- limits the external validity and reliability of the data

Question 6

Weaknesses- patient?

Answer 6

Patient must be completely still- limited range of stimuli/responses can be measured

Question 7

Weaknesses- replication?

Answer 7

Not always possible to replicate some activity in the scanner

Question 9

What does the computer do with fmri’’s?

Answer 9

Transforms the information into a brightly coloured 3D image which is mapped using voxels - each voxel = thousands of neurons
The active areas of the brain can then be compared with areas that are lower in activity which is indicated on the fmri scan image via the degree of bright colour

Question 10

Strengths- spatial resolution?

Answer 10

Have good spatial resolution of 1mm
Can precisely identify the active brain regions and patterns of activation over tie
Can lead to increased insight into how the brain works e.g. the role of dopamine in addiction

Question 11

Strengths- non-invasive?

Answer 11

PPTS are protected from injections of potentially harmful substances- PET scans involve injection of a radioactive tracer into the participant
Means that fMRI has good ethical validity

Question 12

Limitations- slow?

Answer 12

There is a 5 second delay between brain activity and measurement
Could mean that some important information is not detected due to the delay
Cannot prove a theory- can only indicate biological correlations to behaviour