On 10/10/2016 08:20 AM, Qi Ting wrote:
Dear Freesurfer experts,
I am trying to do the group analysis, before this I tried to smooth the data with the different smoothing kernel. However, when I checked the output dir, it turned out that data were smoothed with a larger smoothing kernel than I expected. For example, images intended to be smoothed with 5mm were actually smoothed with 8mm. So does anyone know why?
The 8mm is the measured smoothing level, not the level you applied. Real data have endogenous smoothness that adds to the smoothness you applied to give you a final level of smoothness that is greater than both.
Another thing is about the surface area in the analysis. I am a little confused which surface does the default cmd or the area in qdec indicate? Does it mean the area I got is white surface? If so, can I also get a pial surface? Technically, is the middle between the white surface and the pial surface the more reasonable one?
The one that is just "area" is the area of the white surface. I think there is a option called "area.pial". In general we like to use the area of the white surface because that will be independent of changes in thickness.
Thank you in advance.
Best regards, Ting _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer