What is the purpose of the high-frequency filter in EEG analysis?

The purpose of the high-frequency filter in EEG analysis is to decrease muscle artifact interference. In EEG recordings, muscle activity can generate high-frequency noise that may obscure or distort the brain's electrical signals. By applying a high-frequency filter, these unwanted muscle artifacts are reduced, allowing for a clearer view of the brain's electrical activity. This filtering is crucial for accurately interpreting the EEG data, as it helps isolate the relevant brain waves from extraneous interference caused by muscle contraction or other high-frequency noise sources. This ensures that clinicians can focus on the genuine neurophysiological signals being recorded, leading to more accurate diagnoses and assessments.