in general people have not found much of a relationship between ICV and thickness, so correcting for icv just reduces your # of degrees of freedom without removing any unwanted variance. You can remove the global mean thickness, which is testing a slightly different hypothesis than not doing so.
cheers Bruce On Mon, 25 Jan 2010, lordowen wrote: > Hi, Bruce: > > Why should not be corrected for thickness? Or you mean the cortical > thickness should be corrected using mean thickness but not > intracranial volume? Can you explain more? > > Thank you for your advise. > > 2010/1/23 Bruce Fischl <[email protected]>: >> Hi LJ, >> >> yes, the volume of the amygdala is in the stats/aseg.stats file for each >> subject. There should also be an estimated intracranial volume and brain >> size that you can use to account for either one (which represent somewhat >> different hypotheses). In general I think the consensus is that volumes >> should be corrected, but not thickness. >> >> cheers >> Bruce >> >> >> On Sat, 23 Jan 2010, liyari5018 wrote: >> >>> Hi all, >>> When I completed the recommended recon-all step, I want to get the >>> volume(or size) of amygdala for ecah individual subject and to do >>> correlation analysis with psychological scale, how can I do this ??? For a >>> group level analysis , should i do some head size correction befor ??? >>> >>> Thanks for your reply!!! >>> L J >> _______________________________________________ >> Freesurfer mailing list >> [email protected] >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> > > > > _______________________________________________ Freesurfer mailing list [email protected] https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
