Which filter settings are most appropriate for the EEG?

The choice of filter settings in EEG (electroencephalogram) recordings is crucial for obtaining a clear and clinically useful signal. The primary aim is to capture the brain's electrical activity while minimizing artifacts and noise that can obscure important data.

The settings chosen, characterized by two numbers, represent the low-frequency and high-frequency cutoffs of the filter, respectively. A low-frequency cutoff of 0.3 Hz permits the detection of slow waves and important physiological processes while filtering out very slow drifting artifacts that can arise from patient movement or changes in muscle tension. On the other hand, a high-frequency cutoff of 35 Hz helps in reducing high-frequency noise but still allows the recording of higher frequency brain activities, such as beta waves associated with alertness.

By selecting a low of 0.3 Hz and a high of 35 Hz, it ensures that both the slower and faster rhythms of brain activity are well captured without introducing excessive high-frequency noise that could obscure clinically relevant signals. This combination allows for a comprehensive view of the patient's EEG, making it a standard choice for comprehensive evaluations.