Melara Robert D, Ruglass Lesia M, Fertuck Eric A, Hien Denise A
Department of Psychology, City College, City University of New York, North Academic Center (NAC), Room 7/120, 160 Convent Avenue, New York, NY 10031, USA.
Department of Psychology, City College, City University of New York, North Academic Center (NAC), Room 7/120, 160 Convent Avenue, New York, NY 10031, USA.
Biol Psychol. 2018 Mar;133:89-98. doi: 10.1016/j.biopsycho.2018.01.017. Epub 2018 Feb 1.
The current study investigated links between trauma exposure, Post-traumatic Stress Disorder (PTSD) symptoms, and inhibitory control assessed using a modified version of the visual flanker task. The study had three aims: (1) specifically confirm general non-affective deficits in sustained attention in PTSD; (2) probe the influence of threatening and trauma-related stimuli on inhibitory control; and (3) explore neural correlates connecting PTSD, facets of dissociation, and inhibitory control. Participants with PTSD (n = 16), trauma-exposed individuals without PTSD (TE; n = 14), and healthy controls (n = 15) discriminated line orientations while ignoring temporally flanking lines and images depicting threatening or non-threatening scenes or faces. Electrophysiological recordings were made during task performance. Relative to TE participants, PTSD participants had poor sustained non-affective attention, but nevertheless exhibited greater inhibition of distractors (i.e., high event-related potential [ERP] Rejection Positivity [RP]) to threatening (versus non-threatening) stimuli. RP was associated with greater self-reported depersonalization in PTSD participants, but with less depersonalization in TE participants. Dipole source analysis localized RP to the posterior cingulate cortex in both PTSD and TE (and healthy controls), but with an additional source in the ventromedial prefrontal cortex in TE, components of the default mode network. Results suggest a paradox in the executive control of distraction in PTSD: Whereas individuals with PTSD experience a general impairment in non-affective inhibitory control, their enhanced control of threat is associated with more severe symptoms of dissociation.
本研究使用视觉侧抑制任务的改良版本，调查了创伤暴露、创伤后应激障碍（PTSD）症状与抑制控制之间的联系。该研究有三个目的：（1）明确确认PTSD患者在持续注意力方面存在一般非情感性缺陷；（2）探究威胁性和与创伤相关的刺激对抑制控制的影响；（3）探索连接PTSD、分离症状和抑制控制的神经关联。患有PTSD的参与者（n = 16）、有创伤暴露但无PTSD的个体（TE；n = 14）以及健康对照组（n = 15）在忽略两侧短暂出现的线条以及描绘威胁性或非威胁性场景或面孔的图像的同时，辨别线条方向。在任务执行过程中进行电生理记录。相对于TE参与者，PTSD参与者的持续非情感性注意力较差，但对威胁性（相对于非威胁性）刺激表现出更大的干扰抑制（即高事件相关电位[ERP]拒斥正波[RP]）。RP与PTSD参与者更高的自我报告人格解体相关，但与TE参与者较低的人格解体相关。偶极子源分析将RP定位于PTSD和TE（以及健康对照组）的后扣带回皮层，但TE组在腹内侧前额叶皮层还有一个额外的源，属于默认模式网络的组成部分。结果表明PTSD患者在分心执行控制方面存在矛盾现象：虽然PTSD患者在非情感性抑制控制方面普遍受损，但其对威胁的增强控制与更严重的分离症状相关。
