Castegnetti Giuseppe, Tzovara Athina, Staib Matthias, Paulus Philipp C, Hofer Nicolas, Bach Dominik R
Department of Psychiatry, Psychotherapy, and Psychosomatics, University of Zurich, Zurich, Switzerland.
Neuroscience Centre Zurich, University of Zurich, Zurich, Switzerland.
Psychophysiology. 2016 Jun;53(6):930-9. doi: 10.1111/psyp.12637. Epub 2016 Mar 7.
Across species, cued fear conditioning is a common experimental paradigm to investigate aversive Pavlovian learning. While fear-conditioned stimuli (CS+) elicit overt behavior in many mammals, this is not the case in humans. Typically, autonomic nervous system activity is used to quantify fear memory in humans, measured by skin conductance responses (SCR). Here, we investigate whether heart period responses (HPR) evoked by the CS, often observed in humans and small mammals, are suitable to complement SCR as an index of fear memory in humans. We analyze four datasets involving delay and trace conditioning, in which heart beats are identified via electrocardiogram or pulse oximetry, to show that fear-conditioned heart rate deceleration (bradycardia) is elicited and robustly distinguishes CS+ from CS-. We then develop a psychophysiological model (PsPM) of fear-conditioned HPR. This PsPM is inverted to yield estimates of autonomic input into the heart. We show that the sensitivity to distinguish CS+ and CS- (predictive validity) is higher for model-based estimates than peak-scoring analysis, and compare this with SCR. Our work provides a novel tool to investigate fear memory in humans that allows direct comparison between species.
在不同物种中，线索恐惧条件反射是研究厌恶性巴甫洛夫学习的一种常见实验范式。虽然恐惧条件刺激（CS+）在许多哺乳动物中会引发明显的行为，但在人类中并非如此。通常，自主神经系统活动被用于量化人类的恐惧记忆，通过皮肤电导反应（SCR）来测量。在这里，我们研究由CS引发的心动周期反应（HPR）（在人类和小型哺乳动物中经常观察到）是否适合作为SCR的补充，作为人类恐惧记忆的一个指标。我们分析了四个涉及延迟和痕迹条件反射的数据集，其中通过心电图或脉搏血氧饱和度测定来识别心跳，以表明恐惧条件下的心率减速（心动过缓）被引发，并且能够有力地区分CS+和CS-。然后，我们开发了一个恐惧条件下HPR的心理生理模型（PsPM）。这个PsPM被反转以产生对心脏自主输入的估计。我们表明，基于模型的估计在区分CS+和CS-（预测效度）方面的敏感性高于峰值评分分析，并将其与SCR进行比较。我们的工作提供了一种研究人类恐惧记忆的新工具，允许在不同物种之间进行直接比较。
