■恐惧过度泛化是临床焦虑的一种有希望的致病机制。主导模型认为海马模式分离失败会导致过度泛化。海马网络靶向的经颅磁刺激(HNT-TMS)已被证明可以增强海马依赖性的学习/记忆过程。然而,没有研究检查HNT-TMS是否可以改变恐惧学习/记忆。
■通过基于种子的连接将连续theta爆发刺激传递到个性化的左后顶叶刺激部位,精密功能映射,和电场建模方法。在参与者内部也刺激了顶点控制位点,随机对照设计。在2个视觉辨别任务(1个基于恐惧,1中性)。多水平模型用于建模和测试数据。参与者是有创伤后应激症状的大学生(最终n=25)。
■主要分析没有表明HNT-TMS加强了歧视。然而,多水平交互分析显示,HNT-TMS在多个指标(焦虑等级:β=0.10,95%CI,0.04~0.17,p=.001;风险等级:β=0.07,95%CI,0.00~0.13,p=.037)中增强了较低恐惧敏感性(以对对照刺激的反应为索引,与条件恐惧线索无相似性)的参与者的恐惧辨别。
■过度概括是一种关联过程,反映了对类似线索的恐惧线索的缺乏辨别。相比之下,敏感性反映了与恐惧线索相似性无关的非联想反应。我们的结果表明,当联想反应模式,这可能暗示了海马体,更强烈地参与。
恐惧过度泛化是临床焦虑的一种有希望的致病机制,被认为是由缺乏海马区分力驱动的。在有创伤后应激症状的健康参与者中使用海马网络靶向经颅磁刺激(HNT-TMS),Webler等人。报告称,HNT-TMS并没有加强整体歧视,但它确实加强了恐惧敏感性较低的参与者的恐惧歧视。敏感化反映了与恐惧线索相似性无关的非联想恐惧反应,因此预计不会参与海马辨别功能。这些结果表明,当海马辨别功能更强烈地参与时,HNT-TMS可以选择性地增强恐惧辨别。
UNASSIGNED: Fear overgeneralization is a promising pathogenic mechanism of clinical anxiety. A dominant model posits that hippocampal pattern separation failures drive overgeneralization. Hippocampal network-targeted transcranial magnetic stimulation (HNT-TMS) has been shown to strengthen hippocampal-dependent learning/memory processes. However, no
study has examined whether HNT-TMS can alter fear learning/memory.
UNASSIGNED: Continuous theta burst stimulation was delivered to individualized left posterior parietal stimulation sites derived via seed-based connectivity, precision functional mapping, and electric field modeling methods. A vertex control site was also stimulated in a within-participant, randomized controlled design. Continuous theta burst stimulation was delivered prior to 2 visual discrimination tasks (1 fear based, 1 neutral). Multilevel models were used to model and test data. Participants were undergraduates with posttraumatic stress symptoms (final n = 25).
UNASSIGNED: Main analyses did not indicate that HNT-TMS strengthened discrimination. However, multilevel interaction analyses revealed that HNT-TMS strengthened fear discrimination in participants with lower fear sensitization (indexed by responses to a control stimulus with no similarity to the conditioned fear cue) across multiple indices (anxiety ratings: β = 0.10, 95% CI, 0.04 to 0.17, p = .001; risk ratings: β = 0.07, 95% CI, 0.00 to 0.13, p = .037).
UNASSIGNED: Overgeneralization is an associative process that reflects deficient discrimination of the fear cue from similar cues. In contrast, sensitization reflects nonassociative responding unrelated to fear cue similarity. Our results suggest that HNT-TMS may selectively sharpen fear discrimination when associative response patterns, which putatively implicate the hippocampus, are more strongly engaged.
Fear overgeneralization is a promising pathogenic mechanism of clinical anxiety that is thought to be driven by deficient hippocampal discrimination. Using hippocampal network–targeted transcranial magnetic stimulation (HNT-TMS) in healthy participants with symptoms of posttraumatic stress, Webler et al. report that HNT-TMS did not strengthen discrimination overall, but it did strengthen fear discrimination in participants with lower fear sensitization. Sensitization reflects nonassociative fear responding unrelated to fear cue similarity and therefore is not expected to engage the hippocampal discrimination function. These results suggest that HNT-TMS may selectively sharpen fear discrimination when the hippocampal discrimination function is more strongly engaged.