[ENH] BIDS behavioral file for documenting mouse trajectory onset time

[jungheejung]

Which module are you suggesting enhancements?

events

Is your feature request related to a problem? Please describe:

We have this variable called outcome_motiononset and outcome_motiondur this may become confusion, later when we layer in the term "motion" for head movement in the scanner.

What solution would you like to see?

Change this to mouseonset / mousedur or trajectoryonset / trajectory dur

[jungheejung]

updated in https://github.com/spatialtopology/spacetop-prep/tree/master/spacetop_prep/events