There should be such a sequence for each stimulus type.
And for each stimulus, the corresponding sequence shows
the TRs for which that stimulus is presented to the
subject.

So if you have 3 stim classes (like houses, faces and
donuts), then you should have 3 stimulus timing files
(for each run, presumably). And at each TR, there
should be at most one stim type to get presented, with
many TRs without any presentation (the rest TRs).

HowTo #3 is the subject of one of the AFNI classes,
so it might be worth reading the handout for the class.
Please see:

[afni.nimh.nih.gov]

That directory has ppt, pdf and HTML formatted files.


Unfortunately, the HTML files were "optimized" for Internet
Explorer when they were created by PowerPoint. Which means
Micro$oft didn't bother to follow HTML standards for creating
the documents. So they may not be aligned nicely...


- rick