BioSemi.nl

Hello, I wondered if anyone could help me identify the source of the EEG artifact shown in the attached image . Appears across all sites and continued throughout the recording session. (64 channel system, R-hemi electrodes + EXG shown in image, but occurred on L-hemi also)
I hadn't seen it before this participant or since in subsequent data recordings.
For this person in shielded booth, lights were off, phone non-transmit, no jewelry, watch off, wasn't touching anything electrical that I could see. Offsets looked good, was wearing glasses. I haven't seen for other people in the same set-up. Ideas??? I will see if I can correct this with typical filtering, but ideally I would like to prevent recording it in the first place in future people if I can better understand where it's coming from.

Thanks!
~Jill

60 Hz in a shielded booth means interference by magnetic field. Bundle and twist the electrode wires to minimize enclosed loops.

Best regards, Coen (BioSemi)

Coen, Thank you for your reply.
We always bundle all the cables (A, B, + 8 EXG) and wrap the CMS-DRL lead around the bundle ~3x, and secure with a velcro strap. Can you elaborate upon your recommendation if something beyond these measures we have been implementing?

thank you,
Jill