Dear SPM-DCM experts,
Background:
We have an fMRI-design consisting of 2 session (experimental & control body site) within a patient group. In all sessions a standardized somatosensory stimulation was applied to the subjects. Stimulation at the experimental body site elicited an additional percept which was rated block-wise.
I was wondering whether our paradigm is suitable for the application of DCM? We have pure stimulation conditions, where the contextual modulation is the presence or absence of the additional percept in patients. We thought about concatenating the timecourses of the experimental and control session and investigating the change in the connectivity between the 3 ROIs in the presence (experimental) or absence (control) of the additional percept. Due to the fact that the stimulation and the additional percept are not independent (stimulation elicits additional percept), we are unsure if the paradigm is sufficient for DCM?
Thanks for your advice
Best, Chris
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