Dear Gerhard,
> I am trying to understand the batch mode of SPM and have a question
> about the specification of a model for PET.
>
> In spm_bch.man it says " no PET version for the moment ". This document
> is from the 27.10.99 and it refers to SPM99b. Is it now, with SPM99,
> possible to specify a model for PET? If you call spm_bch without any
> argument you are told that you can choose between fMRI and PET:
>
> » spm_bch
> FORMAT : spm_bch(bch_mfile [,'FMRI'|'PET']
As far as I know the PET mode is not yet implemented. However, if you have a
bit of matlab knowledge, there is a way to change a fMRI model to make it
analyze PET. There are mainly three things: You have to set the TR to a
really high value, say 480 sec. Then you have to estimate the global mean
intensity by spm_global and feed this vector as an additional regressor
into the model and choose no prop. scaling to effect an Ancova. Obviously,
you implement PET 'basis functions' by choosing the right onsets and
box-car basis functions (non convolved with HRF...) with length of one scan.
Hope this helps, Stefan
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