[Eeglablist] How to Clean EEG Data with Large Amplitudes After High-Pass Filtering

[Jiongjiong Li]

Hello,
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 clean this dataset*, since standard filtering does
not seem sufficient?

1. Percent of samples with |amplitude| > 100 µV per channel:
Channel PercentAbs > 100uV
FP1 92.946
FP2 31.312
C3 37.702
C4 34.826
P7 77.775
P8 50.242
O1 85.518
O2 52.286
F7 27.337
F8 42.444
F3 43.282
F4 34.779
T7 25.874
T8 27.634
P3 87.468
P4 69.978

2. Additional channel statistics:
Channel Min Max Mean Std P5 P95
FP1 -1.55E+05 3.98E+05 -0.33667 18173 -18654 14161
FP2 -3312.7 3268.7 -0.056876 243.58 -324.27 353.39
C3 -2650.7 4902.2 -0.064448 330.28 -465.32 490.06
C4 -3082.8 3528.5 -0.052471 269.78 -389.84 426.57
P7 -5018 17516 -0.018368 880.09 -1263.1 1431.4
P8 -2085.9 9144.2 0.11526 404.97 -523.25 638.35
O1 -11920 70997 0.43565 1346 -1509 1743.5
O2 -2705.5 9071.8 -0.014948 293.52 -395.37 447.87
F7 -2894.7 2943.4 0.024095 193.53 -234.4 255.67
F8 -2973.9 2639.3 0.054757 225.84 -314.76 324.82
F3 -4752.6 5627.2 0.08169 517.18 -635.01 672.64
F4 -6333.3 3600.2 0.07269 515.99 -392.74 630.2
T7 -2638.4 2738 0.015915 177.67 -229.59 253.66
T8 -3213.5 3242.7 0.0090257 223.3 -298.77 327.22
P3 -27780 43690 0.80651 2552.2 -3342.1 3681.6
P4 -14668 46330 0.17228 1622.3 -1771.8 1753.2
3. Channel Data Screenshot:
https://urldefense.com/v3/__https://drive.google.com/file/d/1FwlMrvYE1e7zn0mQOYnwG7WtYk1Q3SAh/view?usp=sharing__;!!Mih3wA!CrjzKaf8yxIzQ7S7-hNrGlTX3i4E6i-3GXMBj9uYu71UDEIrHRdtyhGKF0ShjK6kP-r-OnCRDllzIN6CQI-UPeoMk6Wj$ 


Thank you so much for your guidance!

Best Regards,
Jiongjiong