Dear Experts,

I am trying to "back-normalise" significant clusters identified in a qdec analysis (2 groups, thickness as main variable of interest) back into individual subjects so that I can derive cortical statisitcs.

As per previous posts I have been trying to use mri_cor2label but am running into some problems.  My processing is as follows:

1) Identify file of interest which contains 3 clusters (labelled 1.000000 to 3.000000 as viewed in tksurfer and on qdec text output following analysis) significant using Monte Carlo correction 0.05 - mc-z.abs.th13.sig.ocn.annot

2) mri_cor2label --i mc-z.abs.th13.sig.ocn.annot --id 2 --l cluster2

This produces a file called cluster2.label but when I try loading it into tksurfer (tksurfer fsaverage lh inflated - followed by loading of label in menu system) I get the following error message which prevents me from double checking the label:

% ********************      0 nonzero vertices found ********************

label stat field identically zero - setting to 1

1890 unassigned vertices in label - building spatial LUT...

assigning vertex numbers to label...

Couldn't assign 1617 vertices.

1617 unassigned vertices in label - building spatial LUT...

assigning vertex numbers to label...

Couldn't assign 1617 vertices.

My questions are:

1) Why does this occur ?

2) How can I convert my qdec results (eg. mc-z.abs.th13.sig.ocn.annot to label files which I can then propagate to all subjects using mri_label2label).

Thanks.

Mahinda