Herling S, Downs D A, Woods J H
Psychopharmacology (Berl). 1979 Sep;64(3):261-9. doi: 10.1007/BF00427508.
The effects of IM injections of cocaine, d-amphetamine, and pentobarbital were studied in rhesus monkeys whose lever-press responding was maintained under a second-order fixed-interval, fixed ratio schedule of reinforcement. Within each session, fixed-interval components, ending with the IV injection of 30 microgram/kg cocaine (one group of monkeys) or the delivery of a 300 mg food pellet (second group of monkeys), alternated with fixed-interval components ending without an injection of cocaine or the delivery of food (extinction). Drug pretreatments generally caused comparable dose-related decreases in the overall rates of responding reinforced either by cocaine or by food. Response rates during extinction usually increased and then decreased as the dose of each drug increased. An analysis of the drug effects on response rates in different temporal segments of the fixed intervals showed that in both the reinforcement and extinction components, the normally low control rates of responding which occurred earlier in the intervals were usually increased, while higher control rates which occurred later in the intervals were increased less or decreased. Thus, the effects of these drugs were relatively independent of the reinforcing event (food or cocaine) and tended to depend more on the ongoing rate of responding under these conditions.
在恒河猴身上研究了肌肉注射可卡因、右旋苯丙胺和戊巴比妥的效果，这些猴子的杠杆按压反应是在二级固定间隔、固定比率强化程序下维持的。在每个实验时段内，以静脉注射30微克/千克可卡因（一组猴子）或给予300毫克食物颗粒（另一组猴子）结束的固定间隔成分，与不注射可卡因或不给予食物（消退）结束的固定间隔成分交替出现。药物预处理通常会导致可卡因或食物强化的总体反应率出现类似的剂量相关下降。消退期间的反应率通常随着每种药物剂量的增加而先升高后降低。对固定间隔不同时间段内药物对反应率的影响进行分析表明，在强化和消退成分中，间隔前期通常较低的正常对照反应率通常会升高，而间隔后期较高的对照反应率升高较少或降低。因此，这些药物的作用相对独立于强化事件（食物或可卡因），并且在这些条件下更倾向于更多地依赖于持续的反应率。
