>The cluster-extent correction typically works in two steps: first
>applying a height threshold (also known as the primary threshold, or
>cluster-defining threshold), then second calculating corrected p-values
>for the cluster extents formed at that height threshold. In the example
>you presented, I imagine the primary threshold was p<0.01 (uncorrected,
>based on T-map intensity) and the clusters were selected for having
>corrected p-values p<0.05. Needless to say, these results probably
>weren't generated by the combined extent-peak test of Poline et al.
Uncorrected at p<0.01 and corrected at p<0.05 is a possible explanation. But
in another map of this same paper, they also used a height and extent
thresholds at p<0.001. In another paper, the author even used a joint height
and extent threshold of p<0.0001. I think it's rare to use corrected p value
at 0.0001, isn't it?
>SPM by default produces and displays corrected and uncorrected p-values
>for clusters and local maxima when you assess the results from an
Can anybody tell me how SPM calculates the corrected p-value?