How to Process EEG Data with Large Amplitudes After High-Pass Filtering

jiongjiongjiongjiong
edited June 21 in Cyton

I'm working with EEG data collected using a Cyton + Daisy setup. The experiment allows participants to move freely throughout the recording, so I expected a significant amount of motion-related noise.

I applied a 1 Hz high-pass filter, but the data still shows a very large proportion of high-amplitude values. Overall, about 55% of samples have absolute values greater than 100 µV, which seems too high for usable EEG.

My question is: how to process or clean this dataset, since standard filtering does not seem sufficient?

  1. Channel data screenshot:
    Scroll Channel Data Screenshot

  2. Percent of samples with |amplitude| > 100 µV per channel:

  3. Additional channel statistics:

Thank you so much for your guidance!

Comments

  • wjcroftwjcroft Mount Shasta, CA

    Hi Jiong,

    Your Fp1 channel seems to have both huge deflections (eye blinks, head motion?), but also what may be large amounts of mains noise (the high frequency noise) that seems to recur in bursts about 5 times per second. Are you using a notch filter at your correct mains frequency (60 or 50Hz)?

    It is possible that some of the high amplitude excursions in your other channels, P3, P7, O1, may be motion artifacts, as these channels are correlated.

    Regards, William

Sign In or Register to comment.

© Vanilla Keystone Theme 2026