Laties V G, Wood R W, Rees D C
Psychopharmacology (Berl). 1981;75(3):277-82. doi: 10.1007/BF00432438.
External discriminative stimuli can modify the behavioral effects of d-amphetamine. Previous work with the pigeon has demonstrated that some aspects of performance on the fixed consecutive number schedule are changed less if a discriminative stimulus indicates when reinforcement is available. This effect has now been replicated with the rat using both simple and multiple schedules. Moderate doses of d-amphetamine (0.56--1.0 mg/kg) usually produced large decreases in reinforced runs when no external cue indicated the possibility of reinforcement. Adding discriminative stimuli when the number requirement was met decreased the drug effect. As was true in the pigeon, response rate measures did not differ between the two stimulus control conditions. Thus, external stimulus control diminishes the drug effect in both species, despite the fact that key pecking was studied in the pigeon and lever pressing in the rat. Evidence was also seen of a possible increase in discriminative stimulus control by d-amphetamine.
外部辨别性刺激可以改变右旋苯丙胺的行为效应。之前对鸽子的研究表明，如果有辨别性刺激指示何时可获得强化，固定连续数强化程序中某些表现方面的变化会更小。现在使用简单和多重强化程序在大鼠身上重复了这一效应。当没有外部线索表明有强化可能性时，中等剂量的右旋苯丙胺（0.56 - 1.0毫克/千克）通常会使强化反应大幅减少。当达到数量要求时添加辨别性刺激可降低药物效应。和鸽子的情况一样，两种刺激控制条件下的反应率测量结果没有差异。因此，尽管在鸽子中研究的是啄键行为，在大鼠中研究的是压杆行为，但外部刺激控制在两个物种中都会减弱药物效应。还发现了右旋苯丙胺可能增加辨别性刺激控制的证据。
