The neural circuitry involved in delay-related decision making is shown in Figure 1, in comparison with the brain regions implicated in inhibitory response control. Activity in both the ventromedial and dorsolateral PFC, as well as the posterior cingulate cortex, is associated with the discounted value of future rewards in human subjects.194–196 Moreover, heightened discounting is observed in patients with ventromedial PFC or medial orbitofrontal cortex damage.197 However, in rats, medial PFC lesions do not alter discounting,198 while lesions of the orbitofrontal cortex yield equivocal results – increasing delay discounting in one study while decreasing it in another;199, 200 in humans, greater lateral orbitofrontal cortex activity is associated with less discounting.201
