> Can anyone please tell me where to find out what the contrast options mean, such as tau^2 and QE?
tau^2 is the cross-subjects variance and measures the heterogeneity of the group, and QE is the chi-square test that indicates whether the cross-subjects variance is significant at a brain region.
If you run the analysis with the assumption of different variance across the groups (with option -unequal_variance) in 3dMEMA, I believe that 3dMEMA also provides the ratio of the within-group variances that shows whether the two groups have different variability (heteroskedasticity) in a region.
Gang
