Lecture 18

Question 1

For EEG:

1. What does EEG stand for?
2. What is it interested in?
3. How does it do this?
4. Explain how it works

Answer 1

1. Electroencephalography
2. Primarily interested in event related brain potentials (ERPs)
3. Measuring activity of thousands of neurons, measuring postsynaptic acitivty (just as the neuron transmits the signal to the other)
4. Uses a bunch of electrodes, measuring in microvolt

Question 2

What are the advantages of EEG?

Answer 2

Excellent temporal resolution
* Can measure what happens in the brain every millisecond
* High level of temporal precision
* Can precisely determine exactly when activity happens

Question 3

What is the disadvantage of EEG?

Answer 3

Provides very poor spatial resolution

Question 4

List:

1. The purpose of a heat map
2. How to read a heat map

Answer 4

1. Attempts to source localize activity in the brain
2. Warmer colours (e.x. red) represent increased activity

Question 5

In a heat map, where are the warmer colours typically located?

Answer 5

Near the frontal regions of the brain

Question 6

In EEG:

What does the N100 blip on a graph represent?

Answer 6

Event-related potential for measuring visuospatial potential

Question 7

In EEG:

What does P300 represent?

Answer 7

Event related potential for measuring executive function (inhibitory control etc.)

Question 8

What is a characteristic in the EEG of a patient with schizophrenia?

Answer 8

The latency of P300 is longer

Question 9

Define:

Latency

(In EEG)

Answer 9

The time of the blip on the graph, can tell us various information about the brain

Question 10

For PET:

1. What does PET stand for?
2. What is it used for?
3. How is it done?

Answer 10

1. Positron Emission Tomography
2. Investigation for a clinical disorder
3. Injected with a radioactive siotope that attaches to RBCs, track the movement of the RBCs in the brain

Question 11

What are the downsides of PET?

Answer 11

• Expensive
• Requires numerous equipment
• Has to be run by physicist

Question 12

What are the benefits of PET?

Answer 12

Very sensitive to metabolism
* Good for measuring something related to metabolism

Question 13

What was a previous application of PET?

Answer 13

Used to look at link between function and neuroanatomy of the brain

Question 14

What is PET imaging used to look at? Describe the image compared to a normal one

Answer 14

Alzheimer’s Disease
* Healthy participant has a lot of metabolism (warm colours)
* Alzheimer’s patients has drastically reduced metabolism

Question 15

For fMRI:

1. What does fMRI stand for?
2. What does it measure and how?

Answer 15

1. Function Magnetic Resonance Imaging
2. Measures brain activity by identifying changes in blood flow

Question 16

What signals does fMRI measure?

Answer 16

• BOLD signal (Blood Oxygen Level-Depending Flow)
• Heme-properties of hemoglobin (iron in hemoglobin)

Question 17

What can be seen in an fMRI when an individual is performing a certain task?

Answer 17

The brain area correlated with the task that they are performing lights up

Question 18

What relationship are we looking for in an fMRI?

Answer 18

Relationship between blood flow and brain activity, cannot say it is cause-and-effect

Question 19

True or False:

fMRI has good temporal resolution

Answer 19

False, fMRI has very good spatial resolution but poor temporal resolution

Question 20

Why is an MRI machine potentially dangerous?

Answer 20

Has very strong magnets that can cause harm to metal equipment

Question 21

For NIRS:

1. What does NIRS stand for?
2. How does it work?
3. What is it used to measure?

Answer 21

1. Near-Infrared Spectroscopy
2. Uses light source to detect changes in oxygenation of the brain
3. Measures the amount of oxygenated/deoxygenated blood reaching the brain, the change in oxygenated/deoxygenated blood in respect to exercise

Question 22

What are the strengths of NIRS?

Answer 22

Simple and inexpensive technique