Measuring Brain Activity and Modifying Brain Function

Question 1

Strengths of an EEG

Answer 1

Good temporal resolution (can discriminate brief moments)
Relatively cheap
Safe, well-tolerated by patients

Question 2

Weaknesses of an EEG

Answer 2

Poor spatial resolution- cannot differentiate where the brainwaves are coming from.
Typically can only detect activity on the surface of the brain.

Question 3

What is electrophysiology?

Answer 3

Recording the action potential of a single neuron.

Question 4

What is a strength of electrophysiology?

Answer 4

Good for determining the activity of a single neuron.

Question 5

What are limitations of electrophysiology?

Answer 5

High risk of infection as you have to penetrate the brain with a needle.
Can only record individual neurons or a very small group.

Question 6

How does an MRI work?

Answer 6

A magnetic field passes through the head and hydrogen atoms align with the magnetic field. Because different parts of the brain contain different amounts of water, they emit different signals and an image is formed.

Question 7

How does an fMRI work?

Answer 7

Can detect where the oxygenated/deoxygenated blood is in the brain. Brain regions that are activated will have an increase in blood flow to the region.

Question 8

What are the strengths of an MRI?

Answer 8

Very high spatial resolution- know exactly where the brain activity is.
Can identify specific structures.

Question 9

What are the limitations of an MRI?

Answer 9

MRI machines are very expensive.
Requires a specialist facility and staff.
Some safety risks due to large magnet.

Question 10

How does a PET scan work?

Answer 10

Uses a radioactive tracer to visualise glucose metabolism or neurotransmitter function.

Question 11

What are the limitations of a PET scan?

Answer 11

Expensive, specialist equipment and staff need.
Low spatial resolution.
Some risks.