Wagner Katie, Neuringer Allen
Reed College, Portland, OR, USA.
Learn Behav. 2006 May;34(2):111-23. doi: 10.3758/bf03193187.
Operant responses are often weakened when delays are imposed between the responses and reinforcers. We examined what happens when delayed reinforcers were contingent upon operant response variability. Three groups of rats were rewardedfor varying their response sequences, with onegroup rewarded for high variability, another for middle, and the third for low levels. Consistent with many reports in the literature, responding slowed significantly in all groups as delays were lengthened. Consistent with other reports, large differences in variability were maintained across the three groups despite the delays. Reinforced variability appears to be relatively immune to disruption by such things as delays, response slowing, prefeeding, and noncontingent reinforcement. Furthermore, the small effects on variability depended on baseline levels: As delays lengthened, variability increased in the low group, was statistically unchanged in the middle group, and decreased in the high group, an interaction similar to that reported previously when reinforcement frequencies were lowered. Thus, variable operant responding is controlled by reinforcement contingencies, but sometimes differently than more commonly studied repetitive responding.
当在操作反应与强化物之间施加延迟时，操作反应通常会被削弱。我们研究了当延迟强化物取决于操作反应变异性时会发生什么。三组大鼠因改变其反应序列而得到奖励，一组因高变异性得到奖励，另一组因中等变异性得到奖励，第三组因低变异性得到奖励。与文献中的许多报告一致，随着延迟时间延长，所有组的反应都显著减慢。与其他报告一致，尽管存在延迟，但三组之间在变异性上仍保持着很大差异。强化变异性似乎相对不受诸如延迟、反应减慢、预喂和非条件强化等因素的干扰。此外，对变异性的微小影响取决于基线水平：随着延迟时间延长，低变异性组的变异性增加，中等变异性组在统计学上没有变化，高变异性组的变异性降低，这种相互作用类似于之前在降低强化频率时所报告的情况。因此，可变操作反应受强化条件控制，但有时与更常研究的重复性反应有所不同。
