Hi Tessa,
After looking at this in some detail, while still a bit confusing, it seems that the apparent full-volume stats are coming from inclusion of the compcor regressors. If those terms are not included in the model, the results look more as expected (though I do not know exactly what to expect from your analysis).
Getting the proper AM stim types and such would be good, but I do not think that really affected anything (except that the requested contrasts are surely not what you want).
Anyway, I think the strange results have something to do with a global signal type of regression (where the compcor components have task signal included).
But it is still very strange to get such a strong result across the entire volume. I can imagine how that might happen, but it seems so unlikely...
Try re-running your analysis without them included, and see how it looks.
- rick