Abstract: The effects of intravenous chlorpromazine and chlorpromazine-amphetamine anta-gonism on responses maintained by both food delivery (positive learaing) and electricshock avoidance (negative learning) were determined using a multiple schedule of rein-forcements. Two adult rhesus monkeys (Macacus Rhesus) without previous experimen-tal historory were used. The results show: 1. Chlorpromazine suppressed both the positive and negative learning in a dose-dependent fashion in Macacus Rhesus and there was no qualitative difference betweenthese two events. Chlorpromazine had no effect at lower doses (0.1mg/kg), inter-mediate doses (0.2-0.3 mg/kg) decreased the responses to a certain extent and higherdoses (over 0.5 mg/kg) suppressed the overall responses with food delivery and shockavoidance. 2. Under multiple schedule of positive and negative learning there was an obviousantagonistic effect between amphetamine (0.25 mg/kg) and chlorpromazine (0.2-0.3mg/kg) in the Macacus Rhesus. 3. Chlorpromazine (over 0.5mg/kg) induced quietness, drowsiness and apathy,while amphetamine (over 0.5mg/kg) induced excitement, anxiety and tension in theMacacus Rhesus.

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