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Hi Vivien The answer to the question depends on what you are using the temporal derivative for. For example, many people include the temporal derivative at the single-subject level to reduce unexplained variance in the data, but still focus on the canonical HRF for all analyses. In this case, it is perfectly valid to perform 2nd-level t-tests on the contrasts including the canonical HRF. If you're interested in the temporal derivative information at the group level, you can include it in an F test. You can't bring single-subject F tests to the group level; you have to enter the relevant con* files in a second level F test directly. Of course, the results of this F test might be hard do determine, as in a typical case you would know there is a significant effect of the canonical response OR the temporal derivative, but not which. Alternately, if you are interested in using the temporal derivative to investigate differences in latency of hemodynamic response, you may want to refer to Henson et al (2002) http://dx.doi.org/10.1006/nimg.2001.0940 . If you are interested in using the temporal derivative to better model the hemodynamic response, you might try Calhoun et al (2004) http://dx.doi.org/10.1016/j.neuroimage.2003.12.029 . As far as I know there are no differences in how the temporal derivative is incorporated between SPM2 and SPM5...I'm sure someone will correct me if I'm wrong. Hope this helps! Good luck. Jonathan On Thu, Oct 9, 2008 at 9:22 PM, Vivien YJ Tsen <[log in to unmask]> wrote: > Hi all > I have a question on how to perform group level analyses in SPM5 using the > temporal derivative as well. > > So after running F-contrasts at the individual level analyses, how should I > bring these to the group level? Can i still run a one-sample T-test (say for now > I just want to look at one population group)? > > And, is there any difference between SPM2 and SPM5 in regards to > incorporating the temporal derivative information at both the individual and > group level? > > Thank you. > > Vivien >