Hi Darren,
Yes, because I am unable to offer any physiological interpretation of results
obtained using the unmodulated data. Maybe someone else on the list can
offer a meaningful interpretation of unmodulated results.
All the best,
-John
On Monday 11 May 2009 13:01, Darren Gitelman wrote:
> John
>
> From your comments below are you suggesting that one should only look
> at modulated images?
>
> -----
> Darren Gitelman
>
> 2009/5/11 John Ashburner <[log in to unmask]>:
> > The result can probably be explained by methodology, but not physiology.
> >
> > The grey matter volume difference is meaningful, whereas the grey matter
> > concentration difference is essentially just showing registration errors.
> > The original conception of VBM was to partition the data into
> > "macroscopic" differences (encoded by deformations) and "mesoscopic"
> > differences (encoded by the residuals). After several heated discussions
> > here in the FIL, the perspective changed to one of localising regional
> > volumetric differences.
> >
> > Best regards,
> > -John
> >
> >> Our group recently submitted VBM paper on sleep disorder.
> >> One reviewer impugned the negative result of gray matter volume
> >> difference, but the result of gray matter concentration was positive.
> >> What is the best way to explain our result in methodology and
> >> physiology?Woo-Suk , TaeChucheon, Korea
|