EEG - Electroencephalography Instrumentation and Calibration Questions and Answers

Question 1

An EEG technologist is performing a biological calibration. The patient is asked to open and close their eyes, look left and right, and clench their jaw. What is the primary purpose of this procedure?

Accepted Answer

To verify the integrity of the recording system by generating physiological artifacts and confirming correct channel derivations.

Answer

To assess the patient's level of cooperation before starting the recording.

Answer

To warm up the EEG amplifiers and ensure they are functioning.

Answer

To measure the baseline impedance of the scalp electrodes.

Question 2

A differential amplifier's ability to reject signals that are common to both of its inputs is measured by which of the following specifications?

Accepted Answer

Common Mode Rejection Ratio (CMRR)

Answer

Input Impedance

Answer

Low-Frequency Filter

Answer

Sensitivity

Question 3

During an EEG recording, a technologist notices significant 60 Hz artifact across all channels. Which of the following instrument settings should be adjusted to specifically target and reduce this type of interference?

Accepted Answer

Notch Filter

Answer

High-Frequency Filter

Answer

Low-Frequency Filter

Answer

Sensitivity

Question 4

According to the American Clinical Neurophysiology Society (ACNS) guidelines, interelectrode impedances should be within what range for a standard EEG recording?

Accepted Answer

Between 100 Ohms and 10,000 Ohms (10 kOhms)

Answer

Below 100 Ohms

Answer

Above 50,000 Ohms (50 kOhms)

Answer

Exactly 5,000 Ohms (5 kOhms)

Question 5

A technologist changes the sensitivity setting from 7 µV/mm to 10 µV/mm. How will this affect the appearance of a 70 µV spike on the display?

Accepted Answer

The spike will appear shorter.

Answer

The spike will appear taller.

Answer

The spike will become wider.

Answer

The spike's appearance will not change.

Question 6

Which of the following filter combinations would be most appropriate for routine clinical EEG recording to visualize cortical activity while minimizing slow-wave artifact and high-frequency noise?

Accepted Answer

Low-Frequency Filter (LFF) at 1 Hz, High-Frequency Filter (HFF) at 70 Hz

Answer

Low-Frequency Filter (LFF) at 0.1 Hz, High-Frequency Filter (HFF) at 15 Hz

Answer

Low-Frequency Filter (LFF) at 5 Hz, High-Frequency Filter (HFF) at 70 Hz

Answer

Low-Frequency Filter (LFF) at 1 Hz, High-Frequency Filter (HFF) at 35 Hz

An EEG technologist is performing a biological calibration.The patient is asked to open and close their eyes, look left and right, and clench their jaw.What is the primary purpose of this procedure?

An EEG technologist is performing a biological calibration.
The patient is asked to open and close their eyes, look left and right, and clench their jaw.
What is the primary purpose of this procedure?