Hi ,
We have two questions for you.

1.glt question:

We have 4 conditions in our experimental design c1 c2 c3 c4.

The contrast of interest is

(c1+c2)-c3

We wonder if the glt (1 1 -2 0) is appropiate for our purposes,

OR

to combine c1 c2 in the ideal file and then because we will have 3 conditions our glt will be (1 -1 0)


2. We want to create an average intesity map over 3 lags. Is it appropiate to use:

step1. Prepare the datasets(subbriks) to be avereged.

3dmerge -prefix lag5 -1dindex 66 stim_an1+orig
3dmerge -prefix lag6 -1dindex 68 stim_an1+orig
3dmerge -prefix lag7 -1dindex 70 stim_an1+orig

step2. average (voxels with zero intensity are not included)
3dmerge -gzmean -prefix avg_nozero.mean lag5+orig lag6+orig lag7+orig

OR

Step1 Copy treshold data over intensity data
3dmerge -1thoin -prefix lag5 -1dindex 66 stim_an1+orig
3dmerge -1thoin -prefix lag6 -1dindex 68 stim_an1+orig
3dmerge -1thoin -prefix lag7 -1dindex 70 stim_an1+orig


step2 average (voxels with zero intensity are not included)
3dmerge -gzmean -prefix avg_nozero.mean lag5+orig lag6+orig lag7+orig

The resulted brik has a valid statistic behind it?

Thank you .
Regards,
Teodora