Sign-tracking is a form of autoshaping where animals develop conditioned responding directed toward stimuli predictive of an outcome even though the outcome is not contingent on the animal's behavior. Sign-tracking behaviors are thought to arise out of the attribution of incentive salience (i.e., motivational value) to reward-predictive cues. It…

While knowing what to expect is important, it is equally important to know when to expect it and to respond accordingly. This is apparent even in simple Pavlovian training situations in which animals learn to respond more strongly closer to reward delivery. Here we report that the nucleus accumbens core, an area well-positioned to represent…