Different levels of threat imminence elicit distinct computational strategies reflecting how the organism interacts with its environment in order to guarantee survival. Thereby, parasympathetically driven orienting and inhibition of on-going behavior in post-encounter situations and defense reactions in circa-strike conditions associated with sympathetically driven action preparation are typically observed across species. Here, we show that healthy humans are characterized by markedly variable individual orienting or defense response tendencies as indexed by differential heart rate (HR) changes during the passive viewing of unpleasant pictures. Critically, these HR response tendencies predict neural gain modulations in cortical attention and preparatory motor circuits as measured by neuromagnetic steady-state visual evoked fields (ssVEFs) and induced beta-band (19–30 Hz) desynchronization, respectively. Decelerative HR orienting responses were associated with increased ssVEF power in the parietal cortex and reduced beta-band desynchronization in pre-motor and motor areas. However, accelerative HR defense response tendencies covaried with reduced ssVEF power in the parietal cortex and lower beta-band desynchronization in cortical motor circuits. These results show that neural gain in attention- and motor-relevant brain areas is modulated by HR indexed threat imminence during the passive viewing of unpleasant pictures. The observed mutual ssVEF and beta-band power modulations in attention and motor brain circuits support the idea of two prevalent response tendencies characterized by orienting and motor inhibition or reduced stimulus processing and action initiation tendencies at different perceived threat imminence levels.

中文翻译：

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威胁紧迫性调节人类注意力和运动相关大脑回路的神经增益

不同程度的威胁迫在眉睫会引发不同的计算策略，以反映生物体如何与其环境相互作用以保证生存。因此，通常在物种间观察到副交感神经驱动的定向和抑制在遭遇后情况下的持续行为以及与交感神经驱动的动作准备相关的circa-strike条件下的防御反应。在这里，我们表明，健康人类的特征是个体定向或防御反应倾向显着变化，这由被动观看不愉快图片期间的不同心率 (HR) 变化指示。至关重要的是，这些 HR 反应趋势可预测皮层注意和预备运动电路中的神经增益调制，分别通过神经磁稳态视觉诱发场 (ssVEF) 和诱导的 β 波段 (19-30 Hz) 去同步来测量。减速 HR 定向反应与顶叶皮层 ssVEF 功率增加和运动前区和运动区的 β 波段去同步减少有关。然而，加速 HR 防御反应趋势与顶叶皮层 ssVEF 功率降低和皮层运动电路中β带去同步性降低有关。这些结果表明，在被动观看令人不快的图片期间，与注意力和运动相关的大脑区域的神经增益受到 HR 指数威胁迫近度的调节。