If I want to create an epoch object,do i I need the event object？ but the event object needs the stim channel, and I only have the eeg channel. Does this mean that I cannot create an epoch object?
Or how do I get the stmi channel, do I need a specific machine?
@1358467720 – the question you are asking has a lot to do with your setup. I don’t do EEG reserach, but with the MEG our stimulus machine will output a digital trigger to a channel that is collected as part of the datastructure. If your EEG doesn’t have an extra digital trigger input, there are several ways around it - but it is partly dependent on your task. For auditory, you can split the audio and feed the audio signal into one of the unused EEG channels (this can be problematic because audio range is 20-20K frequency and your data is only acquired at a few hundred hz). You can also feed the trigger output pulse into an EEG channel. For video - you can put a photodiode on the screen of the stim computer and feed that back into an EEG channel. These are just some of the techniques I have heard of to get around the lack of trigger channel, while keeping the timing accurate to the stimulus.
So some of this is related to your stimulus setup and the configuration of your acquisition machine. You will have to provide more information for this to be able to be answered.
–Jeff
hello jeff ! thanks for you reply! I’m a new EEG guy, and I didn’t quite understand what stimulus was. I mainly wanted to use mne’s auto-artifact removal function, but this function required an epoch object, which in turn required an event, and which in turn required a stimulus channel.
If you are just looking at resting data — check out the following functions. (Just put a question mark behind the function to get the help). Those will give you the events or epochs back from raw data without a stimulus.
mne.make_fixed_length_events
mne.make_fixed_length_epochs
–Jeff
1 Like
Hi jeff! That would be very helpful for me. Thank you