Performance of instrumental actions in rats is initially sensitive to postconditioning changes in reward value, but after more extended training, behavior comes to be controlled by stimulus-response (S-R) habits that are no longer goal directed. To examine whether sensitization of dopaminergic systems leads to a more rapid transition from action-outcome processes to S-R habits, we examined perf...

We recorded neuronal activity simultaneously in the medial and lateral regions of the dorsal striatum as rats learned an operant task. The task involved making head entries into a response port followed by movements to collect rewards at an adjacent reward port. The availability of sucrose reward was signaled by an acoustic stimulus. During training, animals showed increased rates of responding...

Considerable evidence suggests that, in instrumental conditioning, rats learn the relationship between actions and their specific consequences or outcomes. The present study examined the role of the dorsomedial striatum (DMS) in this type of learning after excitotoxic lesions and reversible, muscimol-induced inactivation. In three experiments, rats were first trained to press two levers for dis...

We assessed the involvement of the orbital prefrontal cortex (PFo), the prelimbic region of the medial prefrontal cortex (PL), and the amygdala in goal-directed behavior. Rhesus monkeys were trained on a task in which two different instrumental responses were linked to two different outcomes. One response, called "tap," required the monkeys to repeatedly touch a colored square on a video monito...

Conditioned reinforcers are Pavlovian cues that support the acquisition and maintenance of new instrumental responses. Responding on the basis of conditioned rather than primary reinforcers is a pervasive part of modern life, yet we have a remarkably limited understanding of what underlying associative information is triggered by these cues to guide responding. Specifically, it is not certain w...

After a relatively small amount of training, instrumental behavior is thought to be an action under the control of the motivational status of its goal or reinforcer. After more extended training, behavior can become habitual and insensitive to changes in reinforcer value. Recently, instrumental responding has been shown to weaken when tested outside of the training context. The present experime...