Quiz Form

Question Date: 15/11/2023

Question: In an electroencephalogram (EEG), increasing the high-pass filter will result in which of the following?

Options:

Reduce electromyography (EMG) artifact
Reduce sweat artifact
Reduce amplitude of all waveforms
Increase amplitude of all waveforms

Correct Answer: Reduce sweat artifact

Explaination: The high-pass filter, also known as the low frequency filter, reduces the amplitude of waveforms below the selected frequency, but only reduces the selected frequencys amplitude in the range of 50%.Low-frequency waveforms on EEG are usually artifacts, with a major artifact coming from sweat. This results in waves that are usually 0.5 Hz or less. A standard low-frequency filter is usually set at 0.5 Hz or 1 Hz. Increasing this filter will further reduce the low frequency sweat artifact. EMG artifact is typically very fast, in the range of 30 Hz or greater. To reduce this artifact, the low-pass filter (high-frequency filter) can be reduced to 30 or 35 Hz from a standard of 70 Hz.