Retzlaff Billie J, Parthum Elizabeth T P, Pitts Raymond C, Hughes Christine E
University of North Carolina Wilmington.
J Exp Anal Behav. 2017 Jan;107(1):65-84. doi: 10.1002/jeab.236. Epub 2017 Jan 11.
Extended pausing during discriminable transitions from rich-to-lean conditions can be viewed as escape (i.e., rich-to-lean transitions function aversively). In the current experiments, pigeons' key pecking was maintained by a multiple fixed-ratio fixed-ratio schedule of rich or lean reinforcers. Pigeons then were provided with another, explicit, mechanism of escape by changing the stimulus from the transition-specific stimulus used in the multiple schedule to a mixed-schedule stimulus (Experiment 1) or by producing a period of timeout in which the stimulus was turned off and the schedule was suspended (Experiment 2). Overall, escape was under joint control of past and upcoming reinforcer magnitudes, such that responses on the escape key were most likely during rich-to-lean transitions, and second-most likely during lean-to-lean transitions. Even though pigeons pecked the escape key, they paused before doing so, and the latency to begin the fixed ratio (i.e., the pause) remained extended during rich-to-lean transitions. These findings suggest that although the stimulus associated with rich-to-lean transitions functioned aversively, pausing is more than simply escape responding from the stimulus.
在从丰富到匮乏条件的可辨别转换过程中延长停顿时间可被视为逃避行为（即，从丰富到匮乏的转换起到厌恶作用）。在当前实验中，鸽子的按键行为由丰富或匮乏强化物的多重固定比率固定比率程序维持。然后，通过将刺激从多重程序中使用的特定转换刺激改变为混合程序刺激（实验1），或者通过产生一段超时时间，在此期间刺激关闭且程序暂停（实验2），为鸽子提供了另一种明确的逃避机制。总体而言，逃避行为受过去和即将到来的强化物大小的共同控制，使得在从丰富到匮乏的转换期间，逃避按键反应最有可能发生，而在从匮乏到匮乏的转换期间次之。尽管鸽子啄了逃避键，但它们在啄之前会停顿，并且在从丰富到匮乏的转换期间，开始固定比率的潜伏期（即停顿时间）仍然延长。这些发现表明，尽管与从丰富到匮乏转换相关的刺激起到了厌恶作用，但停顿不仅仅是对该刺激的简单逃避反应。
