An alternative view is that the predictor of a reward, through Pavlovian conditioning, becomes a conditioned reinfor-cer and a conditioned component of the net rewarding event (104): indeed, that it becomes the leading edge of the reward (105, 106). It is the habit-forming effect of rewards—whether they be unconditioned or conditioned rewards (reward predic-tors)—that requires short-latency, phasic, response-contingent delivery. Rewards delivered immediately after a response are much more effective than rewards delivered even 1 second later; reward impact decays hyperbolically as a function of delay after the response that earns it (107).