Dissociation of pavlovian and instrumental incentive learning under dopamine antagonists

The administration of the dopamine antagonists, pimozide and ol-flupenthixo l. to rats reduced Pavlovian-instrumental transfer when a conditioned stimu lus (CS) that had been paired with a noncontingent food reward was tested o n instrumental performance. The administration of the antagonists during Pa vlovian conditioning and/or testing abolished the enhancement of instrument al performance by the CS. The effect of both antagonists on instrumental in centive learning was then examined. After training in which the rats perfor med 2 responses for different food rewards, they consumed 1 type food under the antagonists and the other type under vehicle during reexposure. When i nstrumental responding was subsequently tested in extinction, performance w as unaffected by whether the rats had been reexposed to the training reward under the antagonists. These results suggest that Pavlovian and instrument al incentive learning are not mediated by a common process.