EEG Electrode Placement and Montages 2

Question 1

In the International 10-20 system, what do the numbers 10 and 20 represent?

Accepted Answer

The percentage of distance between skull landmarks for electrode placement

Answer

The number of electrodes used

Answer

The impedance levels required in kilohms

Answer

The amplifier gain settings

Question 2

Which montage type displays the voltage difference between each electrode and a common reference point?

Accepted Answer

Referential montage

Answer

Bipolar longitudinal montage

Answer

Bipolar transverse montage

Answer

Laplacian montage

Question 3

In a bipolar longitudinal (anterior-posterior) montage, a phase reversal at C3 indicates:

Accepted Answer

Maximum negativity or positivity at C3

Answer

An artifact at the C3 electrode

Answer

The C3 electrode has high impedance

Answer

Activity originating from the contralateral hemisphere

Question 4

The electrode labeled 'Fz' in the 10-20 system is located at:

Accepted Answer

The midline frontal position

Answer

The left frontal region

Answer

The right frontopolar region

Answer

The left frontotemporal junction

Question 5

What is the maximum recommended electrode impedance for routine EEG recording according to ACNS guidelines?

Accepted Answer

5 kOhm

Answer

1 kOhm

Answer

10 kOhm

Answer

20 kOhm

Question 6

An average reference montage calculates each channel's display by:

Accepted Answer

Subtracting the computed average of all electrode voltages from each electrode

Answer

Subtracting the voltage of the nearest neighbor electrode

Answer

Comparing left hemisphere electrodes to right hemisphere

Answer

Using a weighted sum based on electrode distance