Hello,

I am comparing a single subject cluster analysis using 3dmerge/3dclust/3dclust plugin.

With the same parameters (ie threshold 7, rmm 5 and min volume 1160) on a single brik dataset (t statistic) I see 3 different looking functional maps as output. The output of 3dclust does not suggest any clustering has taken place, while that of 3dmerge looks sensible, but shows far less activation than the cluster plugin result.

Comand lines:

3dmerge -prefix merge_data -1noneg -1thresh 7 -1clust 5 1160 dataset+tlrc
3dclust -quiet -prefix clust_data -1noneg -1thresh 7 5 1160 dataset+tlrc

Selections on plugin: dataset+tlrc, keep, volume 1160, cutoff 7, rmm 7 output gui_data


Note that datasets are in talairach space resampled to 3mm cubic. The problem doesnt seem to occur in native space. This doesnt help as I want to run cluster analysis on group data also.

Any ideas greatly appreciated.

Sarah