Williams B A
Department of Psychology, UCSD, La Jolla 92093-0109.
J Exp Anal Behav. 1992 Sep;58(2):287-302. doi: 10.1901/jeab.1992.58-287.
Procedures used to study anticipatory contrast are conceptually similar to those used to study autoshaping, in that two target stimuli signal either higher or lower rates of reinforcement in the following components of the schedule. Despite this signal contingency, anticipatory contrast entails response rates that are higher to the target stimulus followed by the lower rate of reinforcement. To determine the relation between such effects and autoshaping, different variations of the procedure were used in which the signal contingency was presented in the absence of reinforcement in the target components themselves and in which the reinforcement schedules in the different following components were signaled by the same stimulus. Autoshaping effects of this signal contingency were demonstrated when no reinforcement was available during the target-component signals themselves. Intermediate patterns of behavior occurred when reinforcement was available during the target-component signals and when their different following schedules were correlated with the same stimulus. Attempts to isolate these signal and contrast effects functionally by using the signal-key procedure were unsuccessful. The results demonstrate that Pavlovian stimulus contingencies are in competition with the dynamics of anticipatory contrast, thus reducing its occurrence under some circumstances.
用于研究预期对比的程序在概念上与用于研究自动塑造的程序相似，即两个目标刺激在后续的程序组件中分别预示着较高或较低的强化率。尽管存在这种信号偶然性，但预期对比表现为对目标刺激的反应率在较低强化率之后更高。为了确定这种效应与自动塑造之间的关系，使用了该程序的不同变体，其中在目标组件本身没有强化的情况下呈现信号偶然性，并且不同后续组件中的强化程序由相同的刺激预示。当目标组件信号本身期间没有强化时，证明了这种信号偶然性的自动塑造效应。当目标组件信号期间有强化并且它们不同的后续程序与相同刺激相关时，出现了中间行为模式。通过使用信号键程序在功能上分离这些信号和对比效应的尝试未成功。结果表明，巴甫洛夫式刺激偶然性与预期对比的动态相互竞争，从而在某些情况下减少了其出现。
