Research methods

Question 1

What are the 3 scanning techniques?

Answer 1

PET scan, fMRI scan, CAT scan

Question 2

What is a PET scan?

Answer 2

An individual is injected with a small amount of radioactive material - radioactive atom attaches to glucose and therefore identifies glucose metabolism (brain activity) - gamma rays are produced and a high concentration will occur where lots of glucose is being used - high GM is warmer colours and low GM is cooler colours

Question 3

Evaluation of PET scans

Answer 3

+ useful - can help to predict future behaviour - those with lower GM in pre frontal cortex may have problems with impulse control

• invasive procedure and long term effects are unclear meaning a potential risk to harm - ethical issue

Question 4

What are fMRI scans?

Answer 4

A person’s head is placed under a powerful electromagnet - as neural activity increases in the brain, blood flow will also increase to ensure that enough oxygen allows the brain to function - magnets interact with the hydrogen atoms in blood to produce an image of blood flow

Question 5

Evaluation of fMRI scans

Answer 5

+ more ethical - no exposure to radiation so less risk of being harmed by the scan

• usefulness - not everyone can have this scan due to powerful electromagnet - e.g those with a pacemaker

Question 6

What is a CAT scan?

Answer 6

X-rays are passed into the head at multiple angles - useful for detecting the position of a tumour in the brain but not identifying brain functioning and activity

Question 7

Evaluation of CAT scans

Answer 7

+ useful - e.g for planning surgery - can see the layout of the brain structures before physically entering the skull - can be more efficient which lessens the risk of the patient being under anaesthesia for a long time period

• ethics - involves exposure to radiation and so are only used when possible benefits outweigh the risks