Hi all:

       I'm performing the group analysis  on my own data using command line on FS5.1.0 and i'm a little confused about the Clusterwise Correction for Multiple Comparisions. the command is as follows:

      mri_glmfit-sim \
             --glmdir lh.gender_age.glmdir \
            --sim mc-z 10000 4 mc-z.negative \
            --sim-sign neg --cwpvalthresh 0.05\
            --overwrite

      In this command, does the vertex-wise threshold (here, '4') mean that the vertex whose p value is lower than 0.0001 can be considered to used for the Correction for Multiple Comparisions ? likewise, does the sign (here,'neg')  mean that only negtive vertexs can be considered? Is there a criterion which vertex-wise threshold  and sign i should choose?

Hope you can give me some suggestions !