PET scanning techniques
- PET (Position emission tomography) is used to study the brain.
- It picks up hot spots in the brain, enabling us to find out which parts are working at a particular time.
- A radioactive tracer is added to a chemical (usually glucose) that the body uses and is injected into a vein in the arm.
- The tracer provides small, positively charged particles called positrons, which give signals that are recorded.
- As the glucose is used in the brain, this shows up as the area of activity. The recordings can be displayed as images, which are then interpreted.
- A PET scan can be used to study blood flow in the brain.
Reasons for using PET scans as a research method
- Mainly carried out for medical purposes, eg. to check the damage caused by a stroke.
- Is also used in research to map how the brain works, eg. by showing which parts of the brain are active when certain things are done, such as speaking.
PET scans are reliable; they are replicable and the same areas are highlighted
PET scans are valid because their findings match other findings and they do measure what they claim to measure (e.g. the area pinpointed for speech is the same as that found by other methods)
It is hard to pinpoint exact areas of the brain so…