In a few earlier studies, spatilly smoothing was performed before ReHo analysis. However, Mr. LONG Xiang-Yu found that, for some voxels, the ReHo value is very high because spatially smoothing certainly increase the local similarity. That is why we now recommend to perform spatially smoothing after ReHo calculation. Please note that we are not sure which is "better" for group level analysis, especially between-group studies. I suggest you can compare the results.