Fig. 2.

Statistical t maps showing between-group comparison of fMRI BOLD signal by task phase. (A) Between-group comparison during reward anticipation showing higher ventral striatum and anterior cingulate cortex activation in young subjects. The graphs show parameter estimates in these two brain regions in young and old subjects. The glass brain indicates that the ventral striatum and anterior cingulate cortex are the only two brain regions more activated in young subjects during reward anticipation. (B) Group-by-reward outcome interaction showing that young subjects activate the dorsolateral prefrontal and parietal cortices more robustly, whereas older subjects deactivated the medial PFC less than young subjects. Graphs show the parameter estimates in the right dorsolateral PFC and anterior medial PFC in young and old subjects.