Hi Fatima,
Your findings are not surprising. There is plenty of literature describing problems with the VBM technique. You may read e.g., Kennedy et al (2009), Neurobiology of Aging, vol. 10, 1657-1676 and references cited herein.
Ed
On 8 Jul 2011, at 15:02, freesurfer-request@nmr.mgh.harvard.edu wrote:
Hello,
I'm wondering if anyone could help me out with a question I had. For a study I'm working on, I'm comparing the regional brain volumes in adolescents with and without PTSD. I ran VBM analysis and Freesurfer on my subjects and I found some significant results on VBM (however, only using uncorrected p values) and on Freesurfer, I found no group differences in brain regions. Is there an explanation for that?
If anyone has any thoughts I'd really appreciate it. Thank you kindly!
Fatima