Move the "task events" section (now under modalities) to elsewhere in the ToC

[robertoostenveld]

We have the section https://bids-specification.readthedocs.io/en/stable/04-modality-specific-files/05-task-events.html which is under the "Modality specific files" heading. However, _events.tsv as it is described there is not a modality but rather a complement to the other modalities.

The template currently provided is

sub-<label>/[ses-<label>]
    func/
        <matches>_events.tsv
        <matches>_events.json

The template not only applies to func but also to the meg, eeg and ieeg modalities AND to the beh modality.

I propose that the Task events section (with minor edits to the content to include the other modalities) is moved either to the Common principles section, or as a top-level heading next to the Longitudinal and multi-site studies heading which has my preference, see below at (*).

A small improvement would be to simply move the task events section, which is what I propose. A bigger improvement, but more work and more risky to drag on forever, would be to rewrite and take some improvements to beh also into account as being discussed in the thread #573 (comment).

(*) The _sessions.tsv, _scans.tsv, and _events.tsv are all common over modalities and one could consider them all to (potentialy) represent metadata about experimental manipulations at different temporal scales (sessions is ~weeks, scans is ~hour and events is ~seconds). This similarity is why I think it makes sense to represent them closer to each other in the documentation.

[Remi-Gau]

I completely approve of this and would favor the "small improvement" approach first.

[robertoostenveld]

Hmm, having another look at it, I realize that the same argumentation ("it is not a modality specific file") applies to the Physiological and other continuous recordings section, which is right next to Task events. And also to the Genetics descriptor section. Considering that all of those would move to the top level, that organization does not feel optimal.

Logically I would still say that modality specific files contains MRI (func, anat, etc.), MEG, EEG, iEEG and Behaviour (as in beh) and hence documents files that are stored in a modality specific directory. The task, genetics, physiology, but also the sessions therefore might better be organized under the "Modality agnostic files" section.

[sappelhoff]

thanks for pointing this out @robertoostenveld, I think a reorganization might make sense and I think it's a nice small improvement that we should grab, while simultaneously continuing the discussion on behavior modalities in BIDS.

The task, genetics, physiology, but also the sessions therefore might better be organized under the "Modality agnostic files" section.

with "the task" I assume you mean "Task events"

I agree for task events, genetics, and physiology/stimuli --> but feel that sessions has a good place in the "longitudinal" section