Brain imaging techniques

Brain Imaging Techniques: methods used to scan the structure and find the activity of the brain.

MRI :

• Magnetic resonance imaging

• Measures structures within or between brains - comparison.

• Uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.

• A large tube that contains powerful magnets lie in the tube.

• The scan lasts 15-90 mins depending on what part of the brain.

• Provides high resolution still images of the physiology of the brain.

• Pixel counting can be used to identify changes - quantItative.

STRENGTHS: reduced bias due to numerical data

WEAKNESSES: very expensive = low repeatability. Generalisability = babies and young children can’t go, anyone with metal , claustrophobic, autistic, larger people, pace makers.

EEG:

• Electroencephabgraphy

• It measures activity (live activity in the brain)

• Overall picture of activity

• Electrodes attached to the scalp

• Each electrode gives a total picture of electrical events - neurones firing

• Measures states of activity e.g. stages of sleep and epilepsy

• Difficult to locate the source of atypical activity

STRENGTHS: cheap and portable

WEAKNESSES: really impossible to locate the source of atypical activity

PET:

• Positron emission tomography

• Measures activity

• Produce a coloured image of the whole brain - moving (live activity)

• Have an injection in your coroted artery (neck) which has artificial glucose - it is luminous

• So secs delay

• Circulates the blood around the brain and the areas that are highly activated need to use greater amount of fleurodeoryglucose

STRENGTHS: shows the exact areas of the brain

WEAKNESSES: radioactivity so low repeatability and subjective