Selfish or altruistic? Brain connectivity reveals hidden motivesDuring the study, participants were placed in an fMRI scanner and made altruistic decisions driven by an empathy motive (the desire to help a person for whom one feels empathy) or a reciprocity motive (the desire to reciprocate an individual's previous kindness). Simply looking at the functional activity of specific regions of the brain couldn't reveal the motive underlying the decisions. Broadly speaking, the same areas in the brain lit up in both settings. "However, using Dynamic Causal Modeling (DCM) analyses, we could investigate the interplay between these brain regions and found marked differences between empathy- based and reciprocity-based decisions," explains Grit Hein. "The impact of the motives on the interplay between different brain regions was so fundamentally different that it could be used to classify the motive of a person with high accuracy" she continues.