Hello,
Adding to this thread re. smoothness estimates using first level average vs group residuals, in the Eklund et al. (2016 PNAS) paper, the authors note that the group smoothness used by 3dClustSim may be too low (compared with SPM and FSL), because (unlike SPM and FSL) AFNI averages smoothness estimates from the first-level analysis.
In light of this, would it not be more preferable to use residuals form the group analysis to estimate the smoothness?
I appreciate your help clarifying this.