Everly Jessica B, Holtyn August F, Perone Michael
University of Pittsburgh at Greensburg.
J Exp Anal Behav. 2014 Mar;101(2):201-14. doi: 10.1002/jeab.74. Epub 2014 Jan 21.
On multiple fixed-ratio schedules, pausing is extended at the start of a component ending in a small reinforcer (a lean component) but only when this component follows a component ending in a large reinforcer (a rich component). In two experiments, we assessed whether a stimulus correlated with a lean component is aversive and how its function is affected by the preceding component. In Experiment 1, pigeons responded on mixed fixed-ratio schedules ending in large or small reinforcers. Observing responses converted the mixed schedule to a multiple one by producing a stimulus correlated with the current component. Overall, the lean stimulus did not suppress observing, suggesting that it was not sufficiently aversive. In Experiment 2, an escape procedure was used, and pigeons could convert a multiple schedule to a mixed one by pecking a key to remove the discriminative stimuli. Pigeons escaped from the lean-schedule stimulus more than they did from the rich one. For two pigeons, this effect was enhanced when a rich component preceded the lean stimulus. The results indicate that a stimulus correlated with the leaner of two reinforcement schedules can acquire aversive functions, but observing and escape procedures may differ in their abilities to detect this effect.
在多个固定比率强化程序中，停顿在以小强化物结束的成分（贫强化成分）开始时会延长，但只有当这个成分紧跟在以大强化物结束的成分（富强化成分）之后时才会如此。在两项实验中，我们评估了与贫强化成分相关的刺激是否具有厌恶性，以及它的功能如何受到前一个成分的影响。在实验1中，鸽子在以大或小强化物结束的混合固定比率强化程序上做出反应。观察反应通过产生与当前成分相关的刺激，将混合程序转换为多个程序。总体而言，贫强化刺激并未抑制观察反应，这表明它的厌恶性不足。在实验2中，使用了逃避程序，鸽子可以通过啄一个键来移除辨别性刺激，从而将多个程序转换为混合程序。鸽子从贫强化程序刺激中逃避的次数多于从富强化程序刺激中逃避的次数。对于两只鸽子来说，当富强化成分先于贫强化刺激出现时，这种效应会增强。结果表明，与两种强化程序中较贫强化的程序相关的刺激可以获得厌恶性功能，但观察程序和逃避程序在检测这种效应的能力上可能存在差异。
