Variations in interoceptive signals from the baroreceptors (BRs) across the cardiac and respiratory cycle can modulate cortical excitability and so affect awareness. It remains debated at what stages of processing they affect awareness-related event-related potentials (ERPs) in different sensory modalities. We investigated the influence of the cardiac (systole/diastole) and the respiratory (inhalation/exhalation) phase on awareness-related ERPs. Subjects discriminated visual threshold stimuli while their electroencephalogram, electrocardiogram, and respiration were simultaneously recorded. We compared ERPs and their intracranial generators for stimuli classified correctly with and without awareness as a function of the cardiac and respiratory phase. Cyclic variations of interoceptive signals from the BRs modulated both the earliest electrophysiological markers and the trajectory of brain activity when subjects became aware of the stimuli: an early sensory component (P1) was the earliest marker of awareness for low (diastole/inhalation) and a perceptual component (visual awareness negativity) for high (systole/exhalation) BR activity, indicating that BR signals interfere with the sensory processing of the visual input. Likewise, activity spread from the primary visceral cortex (posterior insula) to posterior parietal cortices during high and from associative interoceptive centers (anterior insula) to the prefrontal cortex during low BR activity. Consciousness is thereby resolved in cognitive/associative regions when BR is low and in perceptual centers when it is high. Our results suggest that cyclic fluctuations of BR signaling affect both the earliest markers of awareness and the brain processes underlying conscious awareness.

中文翻译：

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内感受信号塑造了视觉阈值认知的最早标记和神经通路


心脏和呼吸周期中压力感受器 (BR) 内感受信号的变化可以调节皮质兴奋性，从而影响意识。它们在不同感觉模式中的哪个处理阶段影响与意识相关的事件相关电位（ERP）仍然存在争议。我们研究了心脏（收缩期/舒张期）和呼吸（吸气/呼气）阶段对意识相关 ERP 的影响。受试者辨别视觉阈值刺激，同时记录他们的脑电图、心电图和呼吸。我们比较了 ERP 及其颅内发生器，以根据心脏和呼吸时相，在有意识和无意识的情况下正确分类刺激。当受试者意识到刺激时，来自 BR 的内感受信号的周期性变化调节了最早的电生理标记和大脑活动轨迹：早期感觉成分 (P1) 是意识低（舒张/吸气）和低血压的最早标记。高（收缩/呼气）BR 活动的知觉成分（视觉意识负性），表明 BR 信号干扰视觉输入的感觉处理。同样，在高 BR 活动期间，活动从初级内脏皮层（后岛叶）传播到后顶叶皮层，在低 BR 活动期间从联想内感受中心（前岛叶）传播到前额叶皮层。因此，当 BR 较低时，意识在认知/联想区域中得到解决；当 BR 较高时，意识在感知中心中得到解决。我们的结果表明，BR 信号的周期性波动会影响最早的意识标记和潜在意识意识的大脑过程。