You could do as Michael suggested; however, make sure you disable the AR(1) function.

Alternatively, you could skip the concatenation and enter each run as a separate session. This will add the constant term to each run (equivalent to polort=0 in AFNI). For polort=1; you need to create a linear drift term for each session and add it as an additional regressor.

polort is an flag in AFNI's 3dDeconvolve function that specifies the baseline term(s).

The .mat file consists of three variables (onsets, durations, names), if there are more variables it will not be accepted by SPM when you try to run the job file. Each variable is an array. You can download an example from the SPM website.

Best Regards, Donald McLaren
=================
D.G. McLaren
University of Wisconsin - Madison
Neuroscience Training Program
Office: (608) 520-0586
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On Sun, Feb 14, 2010 at 6:11 PM, Gloria Roberts <[log in to unmask]> wrote:

Dear SPM users

 

I have an event related experiment where I would like to concatentate 2 runs. At what stage do I combine my two runs? and at which step do I specify the polort that will be determined by the number of volumes per run?

 

Also my design matrix consists of multiple conditions. I would be grateful if anyone has a template of a .mat file that is needed to specify multiple conditions in the one file.

 

Gloria