在厌恶事件之前的刺激通常不如在非厌恶事件之前的刺激更受欢迎。最近已经证明,较不喜欢的事件之后的刺激可能比更喜欢的事件之后的刺激更受欢迎。这种现象已经以各种名称进行了调查,最常见的是,试验内对比和状态依赖性估值。尽管这种效果已经被复制,已经有几个失败的复制和它仍然是很少理解。本文回顾并总结了有关审判内对比和状态依赖性评估的文献。确定并讨论了研究中的程序差异。然后概述了解释该现象的两个当前模型,并描述了每个模型的局限性。提供了第三种解释,其中包含了激励操作的概念。最后,比较了这三种模型的预测结果。
Stimuli that precede aversive events are typically less preferred than stimuli that precede nonaversive events. It has recently been demonstrated that stimuli that follow less preferred events may become favored more than stimuli that follow more preferred events. This phenomenon has been investigated under a variety of names, most commonly, within-trial contrast and state-dependent valuation. Although this effect has been replicated, there have been several failures to replicate and it is still little understood. This paper reviews and summarizes the literature on within-trial contrast and state-dependent valuation. Procedural variations across studies are identified and discussed. The two current models that explain the phenomenon are then outlined and the limitations of each model are described. A third explanation is offered that incorporates the concept of motivating operations. Last, the predictions of all three models are compared.