Henningfield J E, Meisch R A
Pharmacol Biochem Behav. 1976 Apr;4(4):473-5. doi: 10.1016/0091-3057(76)90066-6.
Two rhesus monkeys were required to emit 1 to 16 responses (FR 1, 2, 4, 8, and 16) per 0.5 ml delivery of either 8% (w/v( ethanol or water. Ethanol had been established as an effective reinforcer via the oral route in an earlier experiment [4]. At FR 16, responding maintained by ethanol clearly exceeded responding maintained by water for both monkeys. The volume of ethanol intake per session remained nearly constant from FR 1 to FR 16, however, the volume of water consumed per session decreased when FR 16 was required.
两只恒河猴被要求在每0.5毫升8%（重量/体积）乙醇或水的输送过程中做出1至16次反应（固定比率分别为1、2、4、8和16）。在早期实验中，乙醇已被确定为经口服途径有效的强化物[4]。在固定比率为16时，两只猴子中由乙醇维持的反应明显超过由水维持的反应。从固定比率1到16，每次实验中乙醇的摄入量基本保持不变，然而，当要求固定比率为16时，每次实验中消耗的水量减少。
