Zukerman Gil, Pinhas Michal, Icht Michal
Department of Communication Disorders, School of Health Sciences, Ariel University, 40700, Ariel, Israel.
Department of Psychology, Ariel University, Ariel, Israel.
Exp Brain Res. 2023 Apr;241(4):1185-1197. doi: 10.1007/s00221-023-06578-w. Epub 2023 Feb 27.
Post-Traumatic Stress Disorder (PTSD) research indicates that hyper-reactivity to trauma-related stimuli reflects reduced prefrontal cortex (PFC) modulation of amygdala reactivity. However, other studies indicate a dissociative "shutdown" reaction to overwhelming aversive stimuli, possibly reflecting PFC over-modulation. To explore this, we used an Event-Related Potential (ERP) oddball paradigm to study P3 responses in the presence of the following: 1. Trauma-unrelated morbid distractors (e.g., "injured bear") related to the Rorschach inkblot test, and 2. Negative distractors (e.g., "significant failure"), among participants with high post-traumatic stress symptoms (PTS; n = 20), low PTS (n = 17), and controls (n = 15). Distractors were presented at 20% frequency amongst the more frequent (60%) neutral standard stimuli (e.g., "desk lamp") and the equally frequent (20%) neutral trauma-unrelated target stimulus ("golden fish"). P3 amplitudes were high in the presence of morbid distractors and low in the presence of negative distractors only amongst the control group. Possible mechanisms underlying the lack of P3 amplitude modulation after trauma are discussed.
创伤后应激障碍（PTSD）的研究表明，对创伤相关刺激的过度反应反映了前额叶皮质（PFC）对杏仁核反应性的调节作用减弱。然而，其他研究表明，对压倒性厌恶刺激会出现分离性“关闭”反应，这可能反映了PFC的过度调节。为了探究这一点，我们使用事件相关电位（ERP）Oddball范式，在以下情况下研究P3反应：1. 与罗夏墨迹测验相关的与创伤无关的病态干扰物（例如，“受伤的熊”），以及2. 消极干扰物（例如，“重大失败”），研究对象包括高创伤后应激症状（PTS；n = 20）、低PTS（n = 17）的参与者以及对照组（n = 15）。干扰物在更频繁出现（60%）的中性标准刺激（例如，“台灯”）和同样频繁出现（20%）的与创伤无关的中性目标刺激（“金鱼”）中以20%的频率呈现。仅在对照组中，病态干扰物出现时P3波幅较高，消极干扰物出现时P3波幅较低。本文讨论了创伤后P3波幅缺乏调节的潜在机制。
