When specifying a FWHM, they may end up being a little bit different because the distance between the vertices is more on the pial than on the white, so you don't need as many iterations to get the same FWHM. Having said that, the difference is pretty darn small between white and pial.

doug

Bruce Fischl wrote:

Hi yczhang,

the smoothing only considers the topology of the surface, so smoothing on the white and the pial are equivalent.

cheers, Bruce

On Tue, 2 Jun 2009, Zhangyuanchao wrote:

...

I am still not quite clear about the averaging of curvature. Sorry about that.

could you tell me exactly which function I should use, and How should I choose each parameter?

First, I get the curvature value of the pial surface, I think I should average the curvature value on the pial surface, perhaps not on white surface, I read help, It seems that It is smoothed on the white surface. How shoud I use the pial to smooth. And I want to keep format of the output file same to the lh.pial.H.crv , and the only difference is the scalar value is smoothed.

Second, I want to obtain the absolute value of the scalar, In this step I will launch "mri_calc".

Third, I want to resample and smooth it using kernel fwhm 20mm.

Thanks!

yczhang

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