Dear Helene,

I cannot answer for the second question, but for the first unfortunately p-uncorrected can never be assimilated to Bonferroni correction, as p-uncorrected does not perform any multiple comparison correction. Even for small volumes, it will always be more optimistic than Bonferroni. For more infos and a demonstration, you can read this excellent wiki page, where they advise to rather show unthresholded maps (but I don't know how well they are received by journal editors): http://imaging.mrc-cbu.cam.ac.uk/imaging/UncorrectedThreshold

An alternative can be to either use voxel-wise FDR, or even cluster-size FDR, as topological (cluster-wise) correction is more liberal than FWE.

Another alternative, particularly if you are doing a single case study, is to use non-parametric correction with a higher cluster-size or cluster-mass threshold than 0.05, using Alfonso's patch which fixes a few edge cases with non-parametric correction:

https://www.nitrc.org/forum/message.php?...

Indeed, it is usually recommended not to raise the cluster-size threshold above 0.05 nor the voxel-wise p-uncorrected threshold of 0.001 when doing parametric correction since Eklund et al's "Cluster failure" paper, because higher thresholds would lead to unquantified and exponentially higher nominal false positive rates, but with non-parametric correction you can use higher thresholds (both at voxel-wise and cluster-wise levels) as they reliably correct to the nominal rate as demonstrated in the same paper (and in others).

Hope this helps,
Stephen Larroque