Probably heresy to say this...
but can't one use the alphasim program that comes with AFNI? It takes in the
image size, a smoothness estimate and p threshold and does a probably
simulation of various cluster sizes.
Darren
---------
Darren Gitelman, MD
Department of Neurology
Northwestern University
voice: (312) 908-8614
fax: (312) 908-5073
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> -----Original Message-----
> From: SPM (Statistical Parametric Mapping)
> [mailto:[log in to unmask]] On Behalf Of Satoru Hayasaka
> Sent: Wednesday, February 20, 2008 11:23 AM
> To: [log in to unmask]
> Subject: Re: [SPM] Combine spatial extent and peak intensity
> to test for activation
>
> > What I mainly want to do actually is to use the algorithm in this
> paper
> > from
> > SPM group "Combining spatial extent and peak intensity to test for
> > activations in functional imaging", J-B. Poline et al, NeuroImage 5,
> 83-
> > 96."
> > to threshold my analysis results generated outside of SPM.
> Unfortunately,
> > Tom said it doesn't exist in SPM any more.
> >
> > Then step back, my question now is how to calculate an adjusted
> > statistical threshold for an analysis outside of SPM given a
> > uncorrected p-value threshold, extent threshold (cluster size), and
> > known voxel number for
> the
> > analysis, which is same as the question Jeff asked in his
> recent post
> > "Calculating adjusted threshold from extent and p-value data" and
> answered
> > by Tom.
>
> Then you can try spm_uc_RF.m function. You might also want to
> check out spm_P_RF.m function, the function which calculates
> corrected p-values.
>
> -Satoru
>
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