Hi,

I've tried a few things since last posting this problem, but the same error remains.

Our study consists of five sessions, each with 136 volumes.
Now, some of the sessions events have only one value to model.
I checked in the SPM structure and all the values including the onset and the corresponding regressor seem to exist.

Is thr a problem if my event has only one value ?

Some of our code:

                SPM.Sess(ses).U(count).P(1).name = 'ArousalScore';
                SPM.Sess(ses).U(count).P(1).h = 1;  % order of polynomial expansion
                SPM.Sess(ses).U(count).P(1).i = [1 2];
                SPM.Sess (ses).U(count).P(1).P = [6.65];
                SPM.Sess(ses).U(count).ons = [274];
                SPM.Sess(ses).U(count).dur = 0; 

I came across the same error even after trying a couple of things. (related to parametric modulation).
Any help would be most appreciated!

Thank you,

Ninad Gujar