Dear Marco,
The only thing that you really need to take into account is the acquisition order of slices. I would generally recommend to use a continuous acquisition order with inter-slice gaps and not to use an interleaved sequence. In the latter case, you run into all sorts of problems with mixing of signals acquired at rather different time points due to head movements or interpolation required during the spatial pre processing. Such temporal errors can be quite detrimental for analyses of effective connectivity.
Other than that, I don’t think you need to worry about anything in particular. In the early days of DCM, we regularly recommended to have a TR not longer than 2 seconds. This requirement is no longer necessary since DCM was augmented with an additional observation equation that allows you to specify precisely at what point in time a given time series was sampled, relative to the first scan (for details see Kiebel et al. 2007, NeuroImage).
All the best,
Klaas
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Von: Marco Sperduti <[log in to unmask]>
An: [log in to unmask]
Gesendet: Dienstag, den 23. Juni 2009, 12:06:45 Uhr
Betreff: [SPM] DCM
Dear SPM users,
I'm new in DCM analysis. I have a little question: are there any experimental's protocol or parameters' acquisition constraints for carrying out a DCM analysis?
Thank you in advance,
Marco
