Do you mean that EOG/ECG events must be detected from multiple channels and the events from different EOG channels should be merged together? Is that what you had in mind? I would have to modify `find_eog_events()` and `find_ecg_events()` too since they accept only a single channel right now.

Or the simpler solution would be to throw an error if the user gives more than one channel.

Which do you prefer?