What is the role of filters in digital EEG recordings?

Filters play a crucial role in digital EEG recordings primarily by removing unwanted noise from the data. The electrical signals captured from the brain, known as EEG signals, can often be contaminated by various types of interference, such as electrical noise from the environment, muscle artifacts (e.g., from facial muscles or eye movements), and other physiological signals.

By applying filters, specific frequency ranges can be emphasized or attenuated. For instance, low-frequency filters can help eliminate slow drift or movement artifacts, while high-frequency filters can reduce the impact of high-frequency noise and aliases. This extraction enhances the clarity and quality of the EEG signals, allowing for more accurate interpretation and analysis.

Filters do not enhance muscle activity, change amplitude directly, or adjust the distance between electrodes. Their primary function is centered around improving the signal-to-noise ratio, thereby facilitating a clearer representation of the brain's electrical activity.