Hello,
I'm analyzing a fast event related working memory experiment that has two different delay conditions ('short' and 'long'). I would like to directly compare activations underlying these two delay conditions. However, I'm concerned because the short delay = 1TR and the long delay =4TRs. Is it statistically inappropriate to make such a comparison (i.e., problem with unequal variances when looking at 1 TR vs 4 TR?)
My strategy thus far has been to extract the percent signal change at each of 11 time points, then use 3dANOVA3 with subjects, time, and condition as factors.
Would alternate methods offered by AFNI be more appropriate? Any suggestions?
Any thoughts would be greatly appreciated,
Chuck