I ran an ANOVA and found main effects of my two variables in several interesting brain regions.
I then ran a conjunction analysis to find the extent to which the clusters for the two main effects overlapped.
I now want to determine the 'size' of the overlap in several specific brain regions that popped up in the conjunction analysis, but I am not sure of the easiest way to do this.
To clarify, in brain region A, I know the cluster size for the Main Effect of Variable A is X mm3 and is Y mm3 for the Main Effect of Variable B. The conjunction analysis shows that that there is an area of overlap that is Z mm3. I want to know what 'Z' is.
Any suggestions? I'm completely sure that I am missing the obvious here, so I just need a little nudge to get my brain going...
