Behavioral conditioned responses across multiple conditioning/testing trials elicited by lithium- and amphetamine-paired flavors.

The present experiment measured the pattern of conditioned responses across 10 conditioning/testing trials which were elicited by an intraoral presentation of either a lithium- or an amphetamine-paired flavor. A nonspecific conditioned response pattern of suppressed limb flicking after five conditioning trials and of suppressed scratching after six conditioning trials was supported by both drugs. Lithium-specific increased activity level after one conditioning trial and chin rubbing after two conditioning trials were observed across conditioning/testing days. The lithium-specific conditioned responses were not the result of a stronger flavor aversion, because both lithium and amphetamine produced equivalent flavor avoidance responses across the 10 conditioning/testing trials. The results support previous research which suggests that flavor aversions produced by lithium and amphetamine are produced by different unconditioned response mechanisms.