BIDS conventions for motion measures/parameters?


I’ve searched and haven’t found anything- in the BIDS scope, is there any language, or any agreed-upon wording for derived motion measures or parameters? For example, 1D data of framewise displacement, per time point, from an fMRI time series.

Specifically, other than having it be a TSV file, would like to know if there is any convention for the final *_suffix.TSV for such derivative data.

Thank you!

I think this is touched upon in the BEP12:

The suffix would be timeseries. I believe this is what the latest versions of fmriprep do.


@effigies should be able to confirm


_timeseries.tsv is the generic container. BEP 012 also permits _timeseries.tsv to be broken into semantically meaningful groups that have constraints on permissible columns. Motion-related time series can be put in _motion.tsv.

1 Like

The motion-related time series section is just what I was looking for.

Thank you both!

Oh, one more question before I mark solved- we want to include many motion-related, summary/calculated single values in one TSV, each one labeled (which would not be a time series, just a column or row of many unrelated values).

Would it be BIDS compliant to name this *_desc-summary_motion.tsv, or does *_motion.tsv imply that it is a time series?

If I were going to put summary values for a given scan, I would either drop them into each scan’s JSON or use the BIDS scans.tsv concept. AFAIK nobody is currently using those as derivatives, but it should be perfectly valid.