Why don’t rats prefer a longer opportunity to run? The current study addressed this question by having rats respond on concurrent fixed ratio (FR) 1 fixed ratio 1 schedules that provided 30-s opportunities to run. Following the termination of one, but not the other wheel-running reinforcement interval, .1 ml of 15% sucrose solution was delivered. Wheel-running reinforcement intervals on both alternatives were systematically decreased across values of 10 s, 5 s, 2.5 s, 1 s, and 0.5 s. Results showed that rats remained indifferent until both alternatives decreased to 2.5 s. At 2.5 s and below a strong preference for the alternative followed by sucrose developed. The correspondence between these results and those for choice between different durations of wheel-running reinforcement implies that revolutions beyond a few seconds also do not affect operant responding. Further research, however, should investigate the effect of stimuli during wheel-running reinforcement intervals on choice between reinforcement of different durations.

为什么老鼠不喜欢更长的跑步机会？当前的研究通过让大鼠对并发固定比率（FR）1固定比率1计划做出响应，从而提供了30 s的跑步机会，从而解决了这个问题。终止一个车轮行驶加固间隔（但不终止另一个车轮间隔）后，输送了0.1 ml的15％蔗糖溶液。在10 s，5 s，2.5 s，1 s和0.5 s的值范围内，两种方法的车轮行驶加固间隔都被系统地减小。结果表明，大鼠保持漠不关心，直到两种选择都降低到2.5 s。在2.5秒及以下的时间，强烈希望使用替代品，然后再开发蔗糖。这些结果与在车轮运行加固的不同持续时间之间进行选择的结果之间的对应关系意味着，超过几秒钟的转数也不会影响操作员的响应。但是，进一步的研究应该研究轮滑加固间隔期间的刺激对不同持续时间的加固之间的选择的影响。