MacDonall J S
Department of Psychology, Fordham University, Bronx, New York 10458, USA.
J Exp Anal Behav. 2000 Sep;74(2):189-206. doi: 10.1901/jeab.2000.74-189.
Concurrent schedules may be viewed as consisting of two pairs of stay and switch schedules, each pair associated with one of the alternatives. A stay schedule arranges reinforcers for staying and responding at one alternative, whereas the associated switch schedule arranges reinforcers for switching to the other alternative. In standard concurrent schedules, the stay schedule at each alternative is equivalent to the switch schedule at the other alternative. MacDonall (1999) exposed rats to one pair of stay and switch variable-ratio schedules and varied the response requirements across conditions. Combining results from symmetric pairs produced composite performances that were described by the generalized matching law. This outcome was noteworthy because the data were obtained from performances at two alternatives with contingencies that were functionally unrelated to each other. This result suggests that concurrent performances may consist of two unrelated performances that alternate as behavior moves between alternatives. The purpose of the present experiment was to extend those results to interval schedules. Rats were exposed to pairs of random-interval schedules, and across conditions their mean intervals were varied. When data from appropriately paired conditions were combined, the composite performances were consistent with the generalized matching law. In addition, the results supported two models of concurrent performances that were based on local variables at an alternative (behavior, and stay and switch reinforcers): a modified version of the contingency discrimination model (Davison & Jenkins, 1985) and the local model (MacDonall, 1999).
并发程序表可以被看作是由两对停留和转换程序表组成，每一对与其中一个选择项相关联。一个停留程序表为在一个选择项上停留并做出反应安排强化物，而与之相关的转换程序表则为转换到另一个选择项安排强化物。在标准的并发程序表中，每个选择项的停留程序表等同于另一个选择项的转换程序表。麦克唐纳（1999年）让大鼠接触一对停留和转换可变比率程序表，并在不同条件下改变反应要求。将对称对的结果结合起来产生了符合广义匹配定律的综合表现。这一结果值得注意，因为数据是从两个功能上相互独立的选择项的表现中获得的。这一结果表明，并发表现可能由两个不相关的表现组成，随着行为在选择项之间转换而交替出现。本实验的目的是将这些结果扩展到间隔程序表。让大鼠接触成对的随机间隔程序表，并在不同条件下改变它们的平均间隔时间。当将适当配对条件下的数据结合起来时，综合表现与广义匹配定律一致。此外，结果支持了基于一个选择项上的局部变量（行为、停留和转换强化物）的两种并发表现模型：权变辨别模型（戴维森和詹金斯，1985年）的一个修改版本和局部模型（麦克唐纳，1999年）。
