Warning When Reading BrainVision Data

Hello everyone,

I’m new to using MNE for processing EEG data. Recently, while reading BrainVision format data, I encountered a RuntimeWarning message:

:1: RuntimeWarning: The unit for channel(s) LEOG, VEOG has changed from C to V.

Here’s the relevant part of my code:

import mne

Reading BrainVision format data

raw = mne.io.read_raw_brainvision(‘2209.vhdr’)

Setting channel types

raw.set_channel_types({“VEOG”: “eog”, “LEOG”: “eog”})

I attempted to set the channel types for VEOG and LEOG to eye movement (eog), but encountered the above warning message. Could someone please explain what this warning message means? How should I properly address this warning?

I’m seeking advice and guidance on how to resolve this issue. Any help would be greatly appreciated!

Thank you!

Maybe they were set as temperature channels (degrees Celsius == C)? You want them to be measured in V though for eog so there really isn’t an issue, it’s just an important message for you to know in case that wasn’t what you wanted.

Thank you for your reply. I think it seems to be a bug. After I used EEGLAB to convert the data to .set files, there was no such problem. :rofl:

1 Like

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.