Mathieu Scheltienne

Please close if there was a reason for the up/down position of the sensor `MEG XXX2`/`MEG XXX3` that I was unaware of.

I assume it was arbitrary as I assumed the files were coming from old Neuromag systems and did not match the one on our DACQ.. I can ask MEGIN directly,...

OK, I'll let you ask then ;)

Renders: - `copy`: https://output.circle-artifacts.com/output/job/223aa771-8bc2-462e-a63d-fe95e0194ef8/artifacts/0/html/generated/mne.channels.Layout.html#mne.channels.Layout.copy - `pick`: https://output.circle-artifacts.com/output/job/223aa771-8bc2-462e-a63d-fe95e0194ef8/artifacts/0/html/generated/mne.channels.Layout.html#mne.channels.Layout.pick

Agree, but I think #11913 will take time, thus I would first merge this PR with a TODO comment left in the codebase and a x-ref to replace the logic...

It would be nice, yes :)

In the eyetracking analysis module, I would have functions which computes a given metric for an eyetracking event, e.g. ``` def compute_saccade_velocity(raw: BaseRaw) -> dict[Annotation, float]: pass ``` which takes...

> This info can/will hopefully in future be generated by a [to be implemented] ET analysis module or [for now] be read from the Eyelink output file. I was applying...

Yes, the events should be present in the `raw`, in the form of annotations. Did I misunderstood something here? IMO, those events can come from 2 sources: the reader or...

I would make this attribute private, and maybe call it `metadata` rather than `userdata` since the goal is to 'hide' it from the user perspective: `annotation._metadata`. For the I/O roundtrip,...