Department of Clinical Psychology, Utrecht University, Utrecht, The Netherlands.
Department of Experimental Psychology, Ghent University, Belgium.
Behav Res Ther. 2018 Nov;110:41-46. doi: 10.1016/j.brat.2018.09.003. Epub 2018 Sep 8.
Verbal instructions are a powerful pathway to learn new fear relations, and an important question has been what fear experience can still add to the effect of such instructions. Therefore, in previous studies, we investigated the effects of pairings between conditioned stimuli (CS) and unconditioned stimuli (US) after CS-US contingency instructions. Although these studies found that CS-US pairings do indeed add to the effects of contingency instructions on subjective, psychophysiological and neural measures of conditioned fear, they also produce increases in US expectancy ratings. In the current report we address whether these enhanced US expectancy ratings can account for the additive effects of CS-US pairings as suggested by expectancy models of fear conditioning. To address this question we made use of pathway models to investigate mediation in within-subjects designs. Our results demonstrate that US expectancy ratings do not mediate the effects of CS-US pairings on fear ratings, the startle reflex or amygdala activation pattern similarity. Additional exploratory analyses, however, revealed that subjective fear ratings do explain the effects of CS-US pairings on the other measures. We discuss how these results relate to expectancy models of fear conditioning and what they implicate for the validity of US expectancy and fear ratings.
口头指令是学习新的恐惧关系的有力途径，一个重要的问题是，什么样的恐惧经验仍然可以增加这种指令的效果。因此，在之前的研究中，我们研究了条件刺激（CS）和非条件刺激（US）之间的配对在 CS-US 关联指令之后的效果。尽管这些研究发现，CS-US 配对确实增加了关联指令对条件恐惧的主观、心理生理和神经测量的效果，但它们也增加了 US 预期评分。在当前的报告中，我们探讨了这些增强的 US 预期评分是否可以根据恐惧条件反射的预期模型来解释 CS-US 配对的附加效果。为了解决这个问题，我们利用途径模型在被试内设计中进行了中介分析。我们的结果表明，US 预期评分不能中介 CS-US 配对对恐惧评分、惊跳反射或杏仁核激活模式相似性的影响。然而，额外的探索性分析表明，主观恐惧评分确实可以解释 CS-US 配对对其他测量的影响。我们讨论了这些结果与恐惧条件反射的预期模型的关系，以及它们对 US 预期和恐惧评分的有效性意味着什么。
