I would like to conduct a group analysis on data convolved with an FIR basis set. After reading SPM8 manual chapter 30 and the SPM archives though I am unclear on what files to import at the 2nd level - from what I read on the SPM list it seems that it should be beta files for each time bin, but SPM8 manual refers to .con images of time bins. Which should it be?
My second question concerns the contrast specification for the FIR: I would like to compare the first half of the epoch to the second using a t-constrast - what would be the best way to do this while having an odd number of time bins (15)? I could specify 14 time bins instead, but this would make a time bin a bit longer than my TR - so I would not be looking at the same volume in each time bin, so it seems like that would be a problem?
I would be really grateful for any input.