Not necessarily. It could have been in the FS analysis. You can run mri_glmfit with --kurtosis (a hidden option). This will create a kurtosis.mgh and pkurtosis.mgh. Kurtosis is a measure of gaussianity of the residuals (larger being less gaussian). The pkurtosis the the sig (-log10(p)) of the probability of seeing the kurtosis under the null (ie, the residuals are gaussian). So you can see if one model gives you better kurtosis than another.
doug On 06/03/2013 01:20 PM, Fotiadis, Panagiotis wrote: > I see. Yes from the one hand the results that I got make a lot more sense in > the second type of analysis, compared to the first one, however, there are > some somewhat important difference between the two analyses. If there is an > issue with the data, do you believe that it would be in the acquisition? > Because I checked the reconstructions and they look fine. > > Thanks, > Panos > ________________________________________ > From: freesurfer-boun...@nmr.mgh.harvard.edu > [freesurfer-boun...@nmr.mgh.harvard.edu] on behalf of Douglas Greve > [gr...@nmr.mgh.harvard.edu] > Sent: Monday, June 03, 2013 11:24 AM > To: freesurfer@nmr.mgh.harvard.edu > Subject: Re: [Freesurfer] Group Analysis Question > > I would not expect them to be identical but similar. If they change a > lot there may be an issue with your data. > doug > > > > On 6/3/13 11:11 AM, Fotiadis, Panagiotis wrote: >> Hey Doug, >> >> I have run a group analysis on my data with two different ways. (The input >> is cortical thickness.) In the first analysis, I specified 4 groups >> (Diseased_Male, Diseased_Female, Healthy_Male, and Healthy_Female) whereas >> in the second, just two groups (Diseased, Healthy). One of the comparisons >> that I did was the age slope between Diseased and Healthy. Therefore in the >> first analysis, I set the contrast vector to be [0 0 0 0 0.5 0.5 -0.5 -0.5] >> and in the second analysis I set it to [0 0 1 -1]. However, the results that >> came up were somewhat different. For instance there were clusters in the >> second analysis that were significant but were not significant in the first >> analysis. >> Shouldn't the results be the same? >> >> Thank you, >> Panos >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > _______________________________________________ > Freesurfer mailing list > 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 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 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.
