Andreatta Marta, Pauli Paul
Department of Psychology, University of Würzburg, Würzburg, Germany.
Department of Psychology, University of Würzburg, Würzburg, Germany; Center of Mental Health, Medical Faculty, University of Würzburg, Germany.
Neurobiol Learn Mem. 2017 Nov;145:105-113. doi: 10.1016/j.nlm.2017.09.005. Epub 2017 Sep 8.
Impaired safety learning has been proposed asa risk factor for anxiety disorders, but safety can be indicated by either threat absence or threat termination (i.e., relief). Here, we investigated the role of trait anxiety for both kinds of safety learning. Ninety-one participants underwent an acquisition phase during which one shape (CS) predicted a painful electric shock (unconditioned stimulus, US), one shape (CS) followed the US, and one shape (CS) became never associated with the US. In a following extinction phase, the three cues were presented again plus a control shape (CS). We found successful threat conditioning as CS was rated as more aversive (negative, arousing, anxiogenic and associated with US) than the other cues, and it elicited startle potentiation as well asa larger skin conductance response (SCR). Safety cues were rated equally positive and (non-)anxiogenic, but still lower than CS, whereas physiologically CS elicited stronger appetitive responses (startle attenuation and low SCR) than CS. Interestingly, an increase in trait anxiety was associated with a decrease in the differences between CS and CS responses reflected in contingency ratings during extinction as well as stronger fear-startle responses to CS. In sum, physiological responses but not ratings triggered by a relief signal compared to a threat-absence signal, indicated that the former is more appetitive than the latter. Strikingly, trait anxiety specifically mediated learning of threat absence, but not of threat termination, indicating that high trait anxious individuals experience relief normally, but have deficits in identifying signals of threat absence.
安全学习受损已被提出是焦虑症的一个风险因素,但安全可以通过威胁不存在或威胁终止(即缓解)来表明。在这里,我们研究了特质焦虑在这两种安全学习中的作用。91名参与者经历了一个习得阶段,在此期间,一种形状(条件刺激,CS)预示着痛苦的电击(无条件刺激,US),一种形状(CS)跟随在US之后,还有一种形状(CS)从未与US相关联。在随后的消退阶段,再次呈现这三种线索以及一个对照形状(CS)。我们发现成功的威胁条件作用,因为CS被评为比其他线索更具厌恶感(负面、引起唤醒、产生焦虑且与US相关),并且它引发了惊吓增强以及更大的皮肤电导反应(SCR)。安全线索被评为同样积极且(非)产生焦虑,但仍低于CS,而在生理上CS引发的积极反应(惊吓减弱和低SCR)比CS更强。有趣的是,特质焦虑的增加与消退期间在偶然性评分中反映的CS和CS反应之间的差异减小以及对CS更强的恐惧惊吓反应相关。总之,与威胁不存在信号相比,由缓解信号触发的生理反应而非评分表明,前者比后者更具积极意义。引人注目的是,特质焦虑专门介导了对威胁不存在的学习,而不是对威胁终止的学习,这表明高特质焦虑个体通常能体验到缓解,但在识别威胁不存在的信号方面存在缺陷。