Thanks Doug. I only now gather that the statistical maps are displayed in terms of the negative common (base 10) logarithm of the p-value.
Two questions:
1) I'm probably wrong here, but if they were displayed (and thresholded) in terms of the corresponding t-value instead, would that not be more convenient since you could also see at a glance the direction of the effect (i.e. whether group A or B has the greater thickness), rather than having to check the group means in the output files of the design?

2) given that p-values lie between 0 and 1, -log10(p) should be between 0 and infinity. How come, then, that the colour-bar also shows negative values?

Tudor

On 4 February 2014 17:09, Douglas N Greve <greve@nmr.mgh.harvard.edu> wrote:

You have the "Min" set to 2 which means that you are not seeing cluster
less significant than p=.01. Try setting it to 1.3 (p=.05)
doug

On 02/02/2014 01:55 PM, Tudor Popescu wrote:
> Dear Freesurfer experts,
>
> I ran a QDEC analysis for structural data and found, after Monte-Carlo
> correction@0.05, one significant cluster, annotated as "postcentral"
> (see screenshot attached). The stats associated with it are displayed
> in the terminal, however the statistical map on the template brain is
> blank.
>
> Also, when I press the "Find Cluster and Go To Max" button, I receive
> an error that no stats can be generated for that cluster.
>
> Not sure if it's relevant, but my dependent variables of interest in
> this analysis were thickness and local gyrification index (lGI). It
> seems I'm getting the above problem only when lGI is the DV, and
> whether or not there is a group factor among the categorical
> predictors. I do have, however, lGI analyses where the significant
> cluster shows up fine both on the template and in the terminal window.
>
> Can anyone help? Many thanks in advance!
>
> Best wishes,
> Tudor
>
>

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