brain scans Flashcards
3 types of brain scans ?
- CAT
- PET
- fMRI
how does PET scans work ?
patient is injected with a radioactive tracer that is taken up by the active areas of the braun, the scanner then picks up the radioactive emissions from the tracer and builds up pictures of active areas
PET - structure of brain functioning ?
it gives good detail on brain functioning and can show the brain in action when doing different tasks, it can also map neurotransmitters in the brain
how long does PET scans take ?
takes 1 hour for radioactive dye to be taken up and another 30-60 mins for the scan
any health risks for PET scans ?
it is an invasive procedure and a higher dose of radiation is given than in a CAT scan, it stays in the body longer but does decay
how much is a PET scanner and scan ?
2-8 million for the scanner
1,400 - 4,000 per scan
an example of using PET scan in psychology ?
raine et al - brain activity in murderes using pet scans
advantages of pet scans ?
- best technique for revealing chemical information for example studying dopamine pathways in SZ
- shows the brain in action
disadvantages of pet scans ?
- very expensive
- invasive procedure therefore can’t use of pregnant women and children, due to health risks
- takes a long time to complete so time consuming and uncomfortable
how do CAT scans work ?
scanning machines takes a series of X-rays and combines them to form a 2 or 3D picture of the brain
structure of brain functioning in CAT scans ?
detailed information on brain structure
how long does CAT scan take ?
relatively quick about 5 mins
any health risks with CAT scans ?
X-rays may be harmful but not in dosage, not recommended for children
how much does CAT scan cost ?
500,000 for scanner
300 - 1600 depending on the type of scan
example of CAT scan in psychology ?
johnstone - used CAT scans to show the brains of SZ were different to normal brains
advantages of CAT scan ?
- good for deleting structural abnormalities like brain tumours or brain structure differences
- cheaper than other methods
disadvantages of CAT scan ?
- cannot tell activity of the brain
- theres significant health risks on PT are exposed to radiation, you could not use it on children for example
how does fMRI work ?
uses magnetic imaging, it scans and takes pictures of the response of brain tissues to strong, magnetic fields. takes a series of pictures so that we can see the brain in action
brain structure or brain function? fMRI
detailed picture of the brain, and can also give good detailed brain functioning when doing different tasks
how long does fMRI take ?
30 - 40 mins
any health risks for fMRI?
lower health risks, no radiation involved
any practical issues for fMRI?
person must remain still, small movements by patient will effect the image in the scanner, in the scanner for a long time so can be uncomfortable and cause claustrophobia
cost for fMRI?
700,000 to 1 mill per scanner
200 - 1500 per scan
example of fMRI scanner in research ?
pardini et al - used fMRI to measure amygdala volume of men and found negative correlation between volume and anti social behaviour
advantage of fMRI ?
- can show structure and activity
- lower health risks than pet and cat as they use magnetic fields
disadvantage of fMRI?
- more costly than cat
- person must stay very still not suitable for claustraphobic people
