Valérie D'Amour-Horvat

Hello, I find myself a bit confused as to which function I should use to combine two ROIs into one (for example, Left and Right Ventral Striatum). Those initial regions were derived from a number labelled mask, and as such, are not based on functional activation from my own participants. I tried both the r1 | r2 function and the r1 + r2 function, and both give me different values when I extract the beta weights for my participants. Is it because the left and right ventral striatum ROIs overlap to...