DCM, in its original inception, was not informed about slice timings of each acquired slice in echo-planar images (EPI) and assumed that all slices were acquired simultaneously. In the first DCM paper (Friston et al., 2003), it has been shown that DCM can cope with slice timing differences of up to 1 s. However, many fMRI studies employ a repetition time (TR) of 3 to 5 s, which precludes a straightforward DCM of these data.

We removed this limitation by including slice timing information into the DCM specification. When entering parameters for a DCM, the user is now asked for the slice timings of each area. In principle, this simple model extension makes it possible to use DCM even on fMRI data acquired with long repetition times and slice-wise acquisition.
 
K.J. Friston, L. Harrison, and W.D. Penny. Dynamic Causal Modelling. NeuroImage, 19(4):1273-1302, 2003.
 
S.J. Kiebel, Stefan Klöppel, N. Weiskopf, and K.J. Friston. Dynamic causal modeling: A generative model of slice timing in fMRI. NeuroImage, 34:1487-1496, 2007.
 
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