If a high-frequency artifact appears in a single EEG channel that shares a reference with other channels, what should be done?

In the context of EEG monitoring, when a high-frequency artifact appears in a single channel that shares a reference with other channels, the approach generally taken involves shifting the focus to a different electrode that is less affected by the artifact. Changing the input signal derivation to a backup exploring electrode allows the technician to gather information from a site that is likely unaffected by the noise or interference contributing to the high-frequency artifact. This method can provide clearer, more accurate data free from the confounding effects of the artifact.

The other options involve manipulating filters or referencing methods that may not effectively address the issue of localized high-frequency artifacts. For instance, simply reducing the high-frequency filter or switching references without choosing a better site could lead to persistence of the artifact or irrelevant data. This choice to use a backup exploring electrode is a proactive way to ensure data integrity, which is essential in sleep studies and other EEG analyses.