Hello
I just wanted to mention a possible typo or possible help for someone with the same question.
I was converting T-stats to z-values with 3dcalc with the expression 't2z_fitt(a,b)', where the volumes a and b are the T-stats and degrees of freedom, respectively.
I just noticed that if the degrees of freedom (b) is 0 in a voxel, then z-value is 13 or -13 depending on sign(a). Why 13, and not 0?
Just in case anyone had the same issue.
Cesar