Connecting Brain and Behavior in the Very Brief Exposure Effect

描述（由申请人提供）：拟议研究的目标是进行迄今为止最严格的假设测试，即恐惧可以在没有意识的情况下减少。两个实验将测试这一假设的大脑和行为，以调查新的无意识恐惧减少的过程及其潜在的实际效用。这一假设挑战了流行的临床信念，即一个令人恐惧的对象必须直接面对充分的意识，以减少恐惧it. The实验范式，非常短暂的曝光，由一系列连续的向后掩蔽的恐惧图像（每个持续时间为33毫秒）。一系列实验表明，VBE减少了对恐惧对象的回避（Siegel，安德森和Han，2011; Weinberger等人，二〇一一年; Siegel & Weinberger，2009年），超过清晰可见暴露（CVE）对相同刺激的影响（Siegel & Weinberger，2012年），并且回避减少效应持续至少一年（Siegel & Warren，出版中）。通过功能磁共振成像和行为学实验研究了VBE的学习机制，并将其与恐惧回避效应联系起来。功能磁共振成像实验将在纽约州立精神病研究所的磁共振成像实验室进行。26名蜘蛛恐惧症和26名非恐惧症的参与者将从纽约州立大学购买学院的文科和理科课程中招募，并使用广泛使用的问卷，行为回避测试（BAT）和DSM-IV诊断的结构化临床访谈。三种类型的暴露中的每一种都将在受试者内进行：非常简短（33.4-ms SOA）和清晰可见（119-ms SOA）的蜘蛛图像，以及非常简短的花图像（对照）。主观恐惧在整个过程中定期进行评级。在没有恐惧体验的情况下，VBE会使杏仁核的激活习惯化，而CVE不会使恐惧反应习惯化并诱导主观恐惧。行为实验将在纽约州立大学采购学院的主要研究者实验室进行。80名蜘蛛恐惧症的参与者-- 26名来自功能磁共振成像实验，74名其他人--将以同样的方式招募。基于对活狼蛛的回避的基线水平，他们将被随机分配到暴露于非常简短（33毫秒SOA）的蜘蛛或花的图像（对照组）。这些暴露将连续三周进行，然后在体内暴露于活狼蛛。主观恐惧将在这些暴露之前和之后进行测量。在功能磁共振成像实验中，VBE对杏仁核激活的减少将预示着对狼蛛的回避减少。VBE将减少避免一个活狼蛛后，第一届会议。对照组受试者在第3次体内暴露前不会获得相同的增益。随后的两届自愿预算外开支会议将取得进一步的成果。这项研究将为R 01提案奠定基础，以进一步研究非常短暂暴露的神经生物学机制，并测试其对临床人群的影响。

DESCRIPTION (provided by applicant): The goal of the proposed research is to conduct the strictest test to date of the hypothesis that fear can be reduced without awareness. Two experiments will test this hypothesis with respect to brain and behavior in order to investigate novel processes of non-conscious fear reduction and their potential practical utility. This hypothesis challenges the prevailing clinical belief that a feared object must be directly confronted with full awareness in order to reduce fear of it. The experimental paradigm, very brief exposure, consists of a continuous series of backward masked phobic images (each for duration of 33-ms). A series of experiments has shown that VBE reduces avoidance of a feared object (Siegel, Anderson & Han, 2011; Weinberger, et al., 2011; Siegel & Weinberger, 2009), more than clearly visible exposure (CVE) to the same stimuli does (Siegel & Weinberger, 2012), and that the avoidance- reducing effect lasts for at least a year (Siegel & Warren, in press). An fMRI and behavioral experiment are designed to identify the learning mechanisms of VBE and link them to its effect on phobic avoidance. The fMRI experiment will be conducted at the MRI Laboratory of the New York State Psychiatric Institute. Twenty-six spider-phobic and twenty-six non-phobic participants will be recruited from liberal arts and science courses at Purchase College/SUNY with a widely used questionnaire, a Behavioral Avoidance Test (BAT), and the Structured Clinical Interview for DSM-IV Diagnosis. Each of three types of exposure will be administered within-subjects: very brief (33.4-ms SOA) and clearly visible (119-ms SOA) images of spiders, and very brief images of flowers (control). Subjective fear is rated periodically throughout. VBE is expected to habituate amygdala activation in the absence of the experience of fear, whereas CVE will not habituate fear responses and induce subjective fear. The behavioral experiment will be conducted in the Principal Investigator's lab at Purchase College/SUNY. 80 spider-phobic participants - 26 from the fMRI experiment, and 74 others - will be recruited in the same manner. Based on baseline levels of avoidance of a live tarantula, they will be randomly assigned to exposure to very brief (33-ms SOA) images of either spiders or flowers (control group). These exposures will be administered each of three consecutive weeks, followed by in vivo exposure to a live tarantula. Subjective fear will be measured just before and after these exposures. Reduction of amygdala activation by VBE in the fMRI experiment will predict reduction of avoidance of the tarantula. VBE will reduce avoidance of a live tarantula after the first session. Control participants will not make the same gain until the 3rd session of n vivo exposure. The two subsequent VBE sessions will result in further gains. The proposed research will lay the groundwork for an R01 Proposal to further investigate neurobiological mechanisms of very brief exposure and test its effects on clinical populations.