What can excessive filtering cause in EEG recordings?

Excessive filtering in EEG recordings primarily affects the low-frequency components of the brain's electrical activity. When filters are set too high or are overly aggressive in removing unwanted signals, they can inadvertently eliminate important slow wave activity, which is crucial for interpreting brain function. These slow waves are typically associated with different states of consciousness, sleep stages, and various neurological conditions.

Loss of slow wave activity results in a significant alteration of the EEG trace, potentially masking key clinical information or leading to misinterpretation of brain states. In clinical practice, it is essential to maintain a balance in filtering to preserve the integrity of the waveform that reflects the brain’s activity.

While increased signal clarity and improved resolution might seem beneficial, they can sometimes come at the expense of essential data, which emphasizes the importance of careful approach to filtering settings. Enhanced artifacts can also result from incorrect filtering, as it can amplify unwanted noise or disturbances rather than eliminate them, further complicating the interpretation of brain function.