What is the primary purpose of a low frequency filter in EEG systems?

The primary purpose of a low frequency filter in EEG systems is to attenuate or eliminate high-frequency noise. Such noise can come from various sources, including electronic interference, muscle activity (artifact), and environmental factors. By employing a low frequency filter, the EEG system is able to focus on the desired brainwave patterns typically found in lower frequency ranges (e.g., delta, theta, and alpha waves) while reducing the impact of these high-frequency disturbances.

In EEG recordings, it is crucial to obtain a clean signal that accurately reflects cerebral activity; thus, filtering out unwanted high-frequency noise helps ensure that clinicians can interpret the data effectively without being misled by artifacts. Low frequency filters are specifically designed to pass the lower frequencies of interest while attenuating frequencies above a certain cutoff, which is important for overall signal clarity and the integrity of the EEG data collected.