Reply-To: | | [log in to unmask][log in to unmask]> wrote: > Hi, > > In my fMRI paradigm, I have 4 conditions (1~4, and conditions 3 and 4 are the main EVs of interest) and 1 time slot of baseline of doing nothing. > > Model 1: > I model the 4 conditions separately. To get activations of the main EV of interest, the contrast is (0 0 1 0) for condirion 3 and (0 0 0 1) for 4. > > Model 2: > I model 1 and 2 conditions together as 1 EV (because they are both EV of no interest) and conditions 3 and 4 separately. To get activations of the main EV of interest, the contrast is (0 1 0) for condirion 3 and (0 0 1) for 4. > > I found the activations of both models are very identical, but it seems that activation in model 2 is slightly larger (and with slightly higher statistics) than that in model 2. > > Which model should I use!? > > Thanks. > > [log in to unmask] |