Hi Reem, it looks like you've done everything correctly (sorry for the null result). As for your second, question, I don't think there is a way other than Bonferroni. You can try FDR, but it makes the interpretation a little messy. doug
On 07/19/2012 07:59 PM, Reem Jan wrote: > > Hi Doug > > I hope it’s okay that I double check I’m doing the correction over 2 > hemispheres correctly and ask a question regarding correction for > multiple comparisons. I will briefly describe what I have done: > > I have 2 groups of subjects – Drug addicts (n= 17) and controls (n=20). > > 1.I ran a surface thickness study: > > ·For the ‘mri_glmfit’ command, I used DOSS and specified a contrast of > +1 -1 0 (Controls > MA) > > ·I ran a pre-cached simulation with the following command: > mri_glmfit-sim --glmdir lh.group_age.glmdir --cache 4 pos > > ·This simulation should only have corrected for the left hemisphere as > I understand it. My cluster summary text file showed me that a cluster > survived in the insula. I interpreted this as ‘controls had higher > grey matter thickness in this cluster located in the insula than drug > addicts’. However, this was only corrected over the left hemisphere > (when I ran the same simulation in the right hemisphere, nothing > survived multiple comparison correction). > > ·I now wanted to correct the lh results for 2 hemispheres. From the > help menu of ‘mri_glmfit-sim’, I understood you can do this in 2 ways, > are both of these correct and give the same result? > > a.mri_glmfit-sim --glmdir lh.group_age.glmdir --cache 4 pos --2 spaces > --no-sim csdbase > > b.mri_glmfit-sim --glmdir lh.group_age.glmdir --cache 4 pos > --cwpvalthresh 0.025 > > ØNo clusters survived the Bonferroni correction over both hemispheres. > So I assume I can no longer report this result? > > 2.I ran a subcortical volume study: > > ·I used SPSS to perform the statistical analysis on each of 14 > subcortical structures (left and right). Is there a good way to > correct for multiple comparisons, apart from Bonferroni, which would > be very conservative? > > Many thanks for your advice. > > Kind regards > > Reem > > *Reem Jan*** > > BPharm (Hons), RegPharmNZ > > PhD Student / Pharmacist > > School of Pharmacy, Faculty of Medical & Health Sciences, > The University of Auckland, Private Bag 92019, > Auckland, New Zealand. > > Ph: +64 9 373 7599 ext 81138. DDI: +64 9 923 1138 > > F: +64 9 367 7192 > > *From:*freesurfer-boun...@nmr.mgh.harvard.edu > [mailto:freesurfer-boun...@nmr.mgh.harvard.edu] *On Behalf Of *Douglas > Greve > *Sent:* Friday, 20 July 2012 11:52 a.m. > *To:* freesurfer@nmr.mgh.harvard.edu > *Subject:* Re: [Freesurfer] slice-by-slice predictors > > Sorry, not possible. > > On 7/19/12 6:56 PM, Caspar M. Schwiedrzik wrote: > > Hi! > Is it possible to have slice-by-slice predictors in Freesurfer, and if > so, how? > Thanks, > Caspar > > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu <mailto: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: www.nmr.mgh.harvard.edu/facility/filedrop/index.html _______________________________________________ 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.
