Hi again!
--- Jiansong Xu <[log in to unmask]> a écrit :
> Dear Friends:
>
> In fMRI, when we state stats threshold, we usually
> say; voxel level
> threshold < .01 (or .05), not corrected, extent
> threshold p < .05
> corrected. In tbss, if I use randomise -c to correct
> multiple
> comparisons, the voxel level threshold is determined
> by the t value
> after the -c option (my understanding). My question
> is how to
> calculate the t value corresponding to voxel level p
> < .05 or p < .01?
http://faculty.vassar.edu/lowry/tabs.html#t
(one-tailed P-value). Then all you need to know are
the degrees of freedom in your statistical model...
Alternatively, you can just report in your manuscript
the t-value you have chosen (it's always arbitrary
anyway, even if 0.05 or 0.01 are somehow more
evocative than 2.4 for instance) and the DOF.
Cheers,
Gwenaelle
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