afni.nimh.nih.gov

yes as gang mentioned, TR = 2.5s. No I want to get response after removing the rest period. So I created new EPI with only the TRs that correspond to task and remove all the rest periods from the file.
I will try 3dDetrend and see how it helps.

I added resting period at the end and it ran fine. Let's see what it does.

Thanks for your help ..