Hello,
I'm having a problem with regressors (EVs) that I've loaded in as
3-column text files. For a 160-volume epi, I have two regressors:
negbase is "on" (value =1) for 1 volume at a time at volumes 32, 40, 64, 88,
112, and 120, and "off" (value=0) the rest of the time. I am not convolving
it with a hemodynamic response function.
negact is on for 4 volumes at a time beginning at volumes 35, 43, 67, 81,
115, and 123.
When I put these in as EV's and look at the resulting model, there are two
problems, which can be seen on the accompanying screenshot:
1) negbase only shows two episodes with valence of 1, not the six that exist
in the regressor text file.
2) the timing doesn't seem correct: the first episode of valence 1 in
negbase should occur at volume 32, but it looks like it occurs in the model
around volume 20.
Any idea why the image of the model seems not to correspond to my regressor
text files?
Thanks,
Jeff
|