Evidence for a shared representation of sequential cues that engage sign-tracking.

Sign-tracking is a phenomenon whereby cues that predict rewards come to acquire their own motivational value (incentive salience) and attract appetitive behavior. Typically, sign-tracking paradigms have used single auditory, visual, or lever cues presented prior to a reward delivery. Yet, real world examples of events often can be predicted by a sequence of cues. We have shown that animals will sign-track to multiple cues presented in temporal sequence, and with time develop a bias in responding toward a reward distal cue over a reward proximal cue. Further, extinction of responding to the reward proximal cue directly decreases responding to the reward distal cue. One possible explanation of this result is that serial cues become representationally linked with one another. Here we provide further support of this by showing that extinction of responding to a reward distal cue directly reduces responding to a reward proximal cue. We suggest that the incentive salience of one cue can influence the incentive salience of the other cue.