Tsukamoto Masashi, Kohara Kenichiro, Takeuchi Koji
Department of Psychology, Graduate School of Humanities, Meisei University, Tokyo, Japan.
Department of Psychology, School of Humanities, Meisei University, 2-1-1, Hodokubo, Hino-shi, Tokyo, Japan.
Learn Behav. 2017 Jun;45(2):135-146. doi: 10.3758/s13420-016-0248-8.
The within-trial contrast hypothesis (WTC) provides a more parsimonious explanation for the phenomenon that humans and animals prefer outcomes that follow more effortful events to outcomes that follow less effortful events (Zentall, 2013). We conducted two WTC experiments with human adults. In Experiment 1, we manipulated the difficulty of a preceding event by varying the interresponse time and the limited-hold interval during differential reinforcement with a low response rate schedule, to examine the effect of effort on the preference for the subsequent stimuli. In Experiment 2, we attempted to identify the variables that had affected the results of Experiment 1, by manipulating time as the delay of reinforcement. The results showed preferences based on WTC only when participants made a high rate of incorrect responses in the preceding event, which was used as an index of the strength of individual effort. These results extend the findings of previous human WTC studies and suggest that the difficulty of a task could serve as an aversive event that affects the WTC effect. It is possible that an index based on performance in the preceding event would provide useful information for predicting the contrast effect.
试验内对比假说（WTC）为人类和动物更喜欢努力程度更高的事件之后的结果而非努力程度较低的事件之后的结果这一现象提供了更为简洁的解释（曾塔尔，2013）。我们对成年人类进行了两项WTC实验。在实验1中，我们通过在低反应率强化程序中改变反应间隔时间和限时保持间隔来操纵先前事件的难度，以检验努力对后续刺激偏好的影响。在实验2中，我们试图通过将时间作为强化延迟进行操纵来确定影响实验1结果的变量。结果表明，只有当参与者在前一个事件中做出高比例的错误反应时才会出现基于WTC的偏好，而前一个事件中的错误反应比例被用作个体努力强度的指标。这些结果扩展了先前人类WTC研究的发现，并表明任务难度可能作为一种厌恶事件影响WTC效应。基于前一个事件表现的指标可能为预测对比效应提供有用信息。
