Threat intensity widens fear generalization gradients.
Threat intensity widens fear generalization gradients.
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DOI：
10.1037/bne0000186
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发表时间：
2017-04
影响因子：
1.9
通讯作者：
Phelps EA
中科院分区：
文献类型：
--
作者：
Dunsmoor JE;Kroes MCW;Braren SH;Phelps EA
对非人类动物的研究揭示了防御行为的威胁敏感性概括，当威胁强度高且概括有限时，这种概括有利于广泛概括（即，当威胁强度较低时。在这里，我们使用巴甫洛夫恐惧条件反射，系统地调查是否威胁强度扩大行为泛化梯度的刺激，减少类似于一个学习的威胁线索。使用受试者之间的设计，志愿者经历了恐惧条件反射与音调配对的高强度或低强度的厌恶刺激之前，恐惧泛化到新的音调测试。结果表明，威胁强度对条件性恐惧的初始获得没有影响。然而，与接受低强度厌恶刺激的志愿者相比，接受高强度厌恶刺激的恐惧调节的志愿者表现出广泛的自主觉醒（皮肤电导反应）泛化。这些结果表明，从正常的过渡（选择性）过度概括的恐惧，威胁强度的增加，并理解过度概括特征的创伤和压力相关的疾病的影响。
Research in non-human animals reveals threat-sensitive generalization of defensive behavior that favors widespread generalization when threat intensity is high and limited generalization (i.e., specificity) when threat intensity is low. Here, we used Pavlovian fear-conditioning to systematically investigate whether threat intensity widens behavioral generalization gradients to stimuli that decreasingly resemble a learned threat cue. Using a between-subjects design, volunteers underwent fear-conditioning with a tone paired with either a high-intensity or low-intensity aversive stimulus prior to a test of fear-generalization to novel tones. Results showed no effect of threat intensity on initial acquisition of conditioned fear. However, volunteers who underwent fear-conditioning with a high-intensity aversive stimulus exhibited widespread generalization of autonomic arousal (skin conductance responses) as compared to volunteers who received a low-intensity aversive stimulus. These results show a transition from normal (selective) to overgeneralized fear as threat intensity increases, and have implications for understanding overgeneralization characteristic of trauma- and stress-related disorders.