Hi Ahmad,
The definition of the driving or modulatory inputs is usually motivated
by the GLM results or some prior knowledge/hypothesis. Thus, you don’t
necessarily need to include all regressors (of interest) into your DCMs.
So, in short (1) a regresssor defined as a modulatory input can be part
of a driving input, (2) you can ignore some regressors if needed, and
(3) you can use the DCM-batch (“dcm_spm8_batch.m”) but you need to make
sure that your DCM.n is equal to 6 (based on the length of your DCM.xY),
with the correct echo time in DCM.TE, and that the right matrices are
used for DCM.a, DCM.b and DCM.c.
I hope this helps,
Mohamed
On 14/11/2012 12:09, Ahmad Ami wrote:
> Dear Expert
>
> i have model with 6 areas ( SMAL,SMAR,M1L,M1R,PHL,PHR)which i have already extracted them and stored in VOI files , and also 5 regressors (inputs). but now i have some questions about specifying the DCM.
>
> 1- Can i use a regressor for driving( direct) input and modulatory input simultaneously, and is this correct way or not.
>
> 2- Can i ignore one of the regressor.
>
> 3-i am using the batch-script for DCM and with this script i able to change the matrices( A,B.C) freely, but with n different modes, then let me know all of the modes are correct or not and i should consider every possibility .
>
>
> thank you for your help in advance.
>
>
> Ahmad
>
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