Greetings Giuseppe!

> there were also some notes about it on Gang's page (which do not seem to exist anymore)

Yes, there were an old webpage about conjunction analysis and an old me too, but the page has been turned. Currently I tend to think that the conventional conjunction analysis is full of issues:

1) inefficient modeling at the whole-brain voxel level,
2) artificial dichotomization,
3) spatial ambiguity,
4) vulnerability to misinterpretations.

> Would it make sense to further multiply this intersection map by the brain-wise complement mask
> of the thresholded and clustered map for the contrast [(cond.A - cond.B) - (cond.C - cond.D)] (that is,
> the mask of non-significant voxels for the latter contrast)?

This is very problematic (the issue 4) above): the absence of strong evidence for an effect cannot be interpreted as the evidence for the absence of the effect.

To avoid these issues, it would be more appropriate to directly define those regions of interest and go from there. These thoughts are discussed here: [afni.nimh.nih.gov]

If you prefer the traditional approach, here is the old page with a lot of yellow stains:
[sscc.nimh.nih.gov]

Gang



Edited 2 time(s). Last edit at 11/18/2021 04:01PM by Gang.