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: > 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 <gr...@nmr.mgh.harvard.edu > <mailto:gr...@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 > gr...@nmr.mgh.harvard.edu <mailto:gr...@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. > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 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 https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
