What intervention most effectively reduces 60 Hz artifact in EEG recordings?

What intervention most effectively reduces 60 Hz artifact in EEG recordings?

• A. Increase the sampling rate
• B. Reposition leads and balance impedance
• C. Switch to a DC-coupled channel
• D. Increase filter bandwidth

Answer: (B)

Reducing mains-frequency interference comes from cleaner, more balanced electrode contacts. When impedance is high or uneven between electrodes, the EEG amplifiers pick up 60 Hz noise more readily, so redoing electrode placement and ensuring impedance is evenly low across channels minimizes the unwanted signal and improves the brain signal clarity. Increasing the sampling rate doesn’t remove the artifact; it may help with temporal resolution but doesn’t eliminate electrical noise. Switching to a DC-coupled channel isn’t a noise-control method for mains interference, since 60 Hz is an AC component. Expanding the filter bandwidth would actually let more 60 Hz noise through instead of suppressing it.

Reducing mains-frequency interference comes from cleaner, more balanced electrode contacts. When impedance is high or uneven between electrodes, the EEG amplifiers pick up 60 Hz noise more readily, so redoing electrode placement and ensuring impedance is evenly low across channels minimizes the unwanted signal and improves the brain signal clarity.

Increasing the sampling rate doesn’t remove the artifact; it may help with temporal resolution but doesn’t eliminate electrical noise. Switching to a DC-coupled channel isn’t a noise-control method for mains interference, since 60 Hz is an AC component. Expanding the filter bandwidth would actually let more 60 Hz noise through instead of suppressing it.