EEG Electrode Placement and Montages 4

Question 1

In the 10-20 system, which electrode is located at the vertex of the skull?

Accepted Answer

Cz

Answer

Cz is located at the vertex (top) of the skull at the intersection of the midline and a line connecting the two ears.

Question 2

What does a referential montage compare each electrode to?

Accepted Answer

A common reference electrode

Answer

In a referential montage, each active electrode is compared to a single common reference electrode, often placed at the ear or linked mastoids.

Question 3

Which electrode placement best captures activity from the temporal lobe?

Accepted Answer

T3/T4 (T7/T8)

Answer

T3/T4 (now called T7/T8 in the revised system) are positioned over the temporal lobes and best capture temporal lobe activity.

Question 4

What is the purpose of the ground electrode in an EEG recording?

Accepted Answer

To reduce common-mode noise and electrical interference

Answer

The ground electrode helps the amplifier reject common-mode noise and electrical interference by providing a reference point for the differential amplifier.

Question 5

In a bipolar longitudinal montage, what is the typical chain order for the left hemisphere?

Accepted Answer

Fp1-F3-C3-P3-O1

Answer

The standard longitudinal bipolar (double banana) chain runs from front to back: Fp1-F3-C3-P3-O1 for the left parasagittal chain.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Electrode Placement and Montages 4