The value displayed is actually sign(effect)*log10(p), which I think answers both of your questions doug
On 02/04/2014 01:00 PM, Tudor Popescu wrote:
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:
- 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 mailto: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 > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer -- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu> Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html <http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html> Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.