Fear inhibition in posttraumatic stress disorder

描述(申请人提供)：创伤后应激障碍(PTSD)患者尽管有安全信号，但仍有持续的恐惧。尽管无法抑制恐惧是创伤后应激障碍的一个中心问题，但它还没有得到很好的研究。本研究的目的之一是评估恐惧增强和恐惧抑制在人类中是独立的过程。这项研究将使用声音惊吓反应的恐惧增强作为恐惧的衡量标准，因为它已经在许多不同的物种中观察到，而且它的神经关联是众所周知的。这项研究的第一部分将翻译一个在动物身上验证的条件歧视程序(AX+/BX-)，以量化创伤后应激障碍的恐惧抑制。此外，我们将测试受试者是否在认知上意识到实验刺激之间的偶然性。先前的研究已经发现，应急意识在产生恐惧强化的惊吓中起着关键作用。本研究将探讨在创伤后应激障碍受试者中，意识如何与惊吓相互作用。最后，本研究将考察权变意识和恐惧抑制之间的关系。

DESCRIPTION (provided by applicant): Patients with posttraumatic stress disorder (PTSD) have persistent fear despite the presence of safety signals. Although the inability to inhibit fear is a central problem in PTSD, it has not been well studied. One of the goals of the present study is to assess fear potentiation and fear inhibition as independent processes in humans. This study will use fear potentiation of the acoustic startle response as a measure of fear, given that it has been observed across many different species and its neural correlates are well known. The first part of the study will translate a conditional discrimination procedure (AX+/BX-), validated in animals, in order to quantify fear inhibition in PTSD. Furthermore, we will test whether the subjects are cognitively aware of the contingencies between the experimental stimuli. Previous research has found that contingency awareness plays a key factor in developing fear-potentiated startle. The present study will investigate how awareness interacts with startle in PTSD subjects. Finally, the present study will examine the relationship between contingency awareness and fear inhibition.