Neuroimaging

Question 1

What is electrophysiology?

Answer 1

An electrode is inserted into a neurone, measures electrical activity of that single neurone

Question 2

What are 2 issues with the use of electrophysiology?

Answer 2

• Only single neurones or a small population of neurones can be recorded at one time
• Cannot be used to obtain information on higher cognitive functions or skills as only animal models can be used

Question 3

How is an EEG used?

Answer 3

Electrodes placed on top of the scalp which can record voltage changes produced by synaptic activity.

Often look at Event Related Potential (ERP), response to stimulus

Question 4

What are strengths and weaknesses of EEG?

Answer 4

Strengths:
• High temporal resolution

Weaknesses:
• Low spatial resolution, very difficult to localise signal sources

Question 5

How does Positron Emission Tomography (PET) work?

Answer 5

Used circular scintillation detector round the head of the subject to localise positron emission.

Radioactive isotopes injected intravenously

Question 6

What are some strengths and weaknesses of PET?

Answer 6

Strengths:
• Give measurements in absolute units

Weaknesses:
• Low spatial and temporal resolution

• Use of radioactivity limits repeated experiments using the same subject
• Injection of radioactivity means stimuli have to be applied for a long time (around 3 mins) as it takes a while to reach the brain