Volumetric smoothing in particular is not advised, as it causes signal from one bank of a sulcus to bleed into the opposite bank. Analyses that average all signal within an ROI should have no benefits (and will have detriments) from smoothing, as the within-ROI averaging itself is a form of smoothing (but with a well-chosen ROI, it won't bring in signal from the opposite sulcal bank, etc, in theory). Is this the kind of ROI analysis you are doing? If so, I wouldn't trust the differences caused by adding volume-based smoothing, because they could be from nearby areas instead.
Tim On Tue, May 29, 2018 at 4:24 PM, David Hofmann <[email protected]> wrote: > Dear all, > > as far as I read in previous posts on the list, spatial smoothing of the > volumetric resting state data is not recommended. But this was with > regard to group ICA. > Would you also recommend not to apply any further spatial smoothing for > the (volumetric) resting state data, when running ROI-based (group) > analysis on multiple subjects? > > Comparing the results of smoothed (4,6, FWHM) and unsmoothed data gives > highly different results in my case, so I'm a bit confused now. > > greetings > > David > > _______________________________________________ > HCP-Users mailing list > [email protected] > http://lists.humanconnectome.org/mailman/listinfo/hcp-users > _______________________________________________ HCP-Users mailing list [email protected] http://lists.humanconnectome.org/mailman/listinfo/hcp-users
