Hi - that's right, assuming that you're ignoring spatial
autocorrelation (smoothness), which would reduce the number of
independent voxels.
Cheers.
On 27 Feb 2008, at 16:10, Yvonne Brehmer wrote:
> Hi Greg, hi Steve,
>
> thanks for your detailed feedback. To sum up: The correct formular to
> calculate the STD of %SC would be:
>
> sqrt(varcope_psc) = sqrt(varcope)*(cope_psc/cope)
>
> and for the calculation of the SE of the mean:
>
> sqrt(varcope_psc)/ sqrt(number of voxels)
>
> I would very much appreciate a short feedback on that.
>
> Thanks,
> Yvonne
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
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