Hi Laura, I assume the input is area? Then this will compute the average area of each vertex. The area of a vertex is the average area of the triangles around it. To get total area, you can multiple the number that you get from xxx.ocn.y.dat by the number of vertices in the cluster.
doug
ps. What version of FS are you using? If not 5.2, do you have the patch to fix the area and volume analysis?
On 03/21/2013 12:52 PM, Laura M. Tully wrote:
hi Doug, A follow up question: when I look at the xxx.ocn.y.dat for a cluster where group differences in surface area have been identified the values are all less than 1 (e.g. 0.761374) even though the cluster size is reported as 680 mmsq. does the y value correspond to .76 mmsq average area for that subject in that cluster or does the y value in the context of surface area analyses represent something else? (or does it need to be multiplied by some factor?)
Thanks!
On Wed, Mar 20, 2013 at 2:39 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu mailto:greve@nmr.mgh.harvard.edu> wrote:
They are the input (mri_glmfit --y y.mgh) averaged over the clusters. They are raw input, no detrending. doug On 03/20/2013 05:16 PM, Laura M. Tully wrote: > Hello experts, > > could someone clarify for me what the y values in the xxx.ocn.y.dat > files represent following glmfit-sim? are they the residualized y > values of avg cortical thickness in that specific cluster after > regressing out the effect of any predictor variables in the glm? > > Thanks! > > Laura. > -- > -- > Laura M. Tully, MA > Social Neuroscience & Psychopathology, Harvard University > Center for the Assessment and Prevention of Prodromal States, UCLA > Semel Institute of Neuroscience > ltully@mednet.ucla.edu <mailto:ltully@mednet.ucla.edu> <mailto:ltully@mednet.ucla.edu <mailto:ltully@mednet.ucla.edu>> > ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu> <mailto:ltully@fas.harvard.edu <mailto:ltully@fas.harvard.edu>> > 310-267-0170 <tel:310-267-0170> > -- > My musings as a young clinical scientist: > http://theclinicalbrain.blogspot.com/ > Follow me on Twitter: @tully_laura > > > _______________________________________________ > 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 <tel:617-724-2358> Fax: 617-726-7422 <tel:617-726-7422> Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> FileDrop: 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.--
Laura M. Tully, MA Social Neuroscience & Psychopathology, Harvard University Center for the Assessment and Prevention of Prodromal States, UCLA Semel Institute of Neuroscience ltully@mednet.ucla.edu mailto:ltully@mednet.ucla.edu ltully@fas.harvard.edu mailto:ltully@fas.harvard.edu 310-267-0170 -- My musings as a young clinical scientist: http://theclinicalbrain.blogspot.com/ Follow me on Twitter: @tully_laura