An associative analysis of pretreatment effects in gustatory conditioning by amphetamine.

Various attempts have been made to account for the fact that pertreatment with some pharmacological agents reduces the ability of such agents to induce conditioned aversion to a flavor. One explanation, based on the concept of tolerance, suggests that pretreatment is effective because it renders the animal less sensitive to direct effects of a given dose of the agent. A second explanation emphasizes the possibility that procedural consequences of pretreatment interfere with associability of flavor and drug effect during conditioning. The second explanation was tested in two experiments. In experiment I nonreinforced presentations of drug administration cues completely reversed the attenuating effects of amphetamine pretreatment on gustatory conditioning by amphetamine. This finding was replicated and extended in the second experiment which was also designed to eliminate an alternative nonassociative explanation for the results. The principle of associative blocking may explain the effect of pretreatment on subsequent gustatory conditioning by drugs.