Leupin Viviana, Britz Juliane
Department of Psychology, University of Fribourg, University of Fribourg, Rue P.-A. Faucigny 2, Fribourg, CH-1700, Switzerland.
Sci Rep. 2025 Aug 11;15(1):29401. doi: 10.1038/s41598-025-12518-1.
Respiration influences brain activity and awareness through two mechanisms: direct rhythmic entrainment via olfactory bulb (OB) stimulation and indirect modulation through baroreceptor (BR) activity fluctuations that affect cortical excitability. During nasal breathing, both mechanisms are active and can influence sensory event-related potentials (ERPs). To isolate the contribution of BR activity, we tested the same paradigm during oral breathing, which eliminates OB stimulation. Results showed that sensory ERPs varied with the cardiac (with delayed timing) but not with the respiratory phase. The P3a component was modulated by awareness only when BR activity was low (during inhalation and diastole), while the visual awareness negativity (VAN) and P3b were modulated by awareness across all conditions. These findings indicate that BR fluctuations alone cannot fully account for the respiratory modulation of awareness-related ERPs, but they require entrainment of brain activity modulated by mechanical OB stimulation.
一种是通过嗅球（OB）刺激进行直接节律性同步，另一种是通过影响皮质兴奋性的压力感受器（BR）活动波动进行间接调节。在鼻腔呼吸过程中，这两种机制均起作用，并可影响感觉事件相关电位（ERP）。为了分离BR活动的作用，我们在口腔呼吸过程中测试了相同的范式，该范式消除了OB刺激。结果显示，感觉ERP随心脏活动（有延迟）而变化，但不随呼吸相位而变化。仅当BR活动较低时（吸气和舒张期），P3a成分才受意识调节，而视觉意识负波（VAN）和P3b在所有条件下均受意识调节。这些发现表明，仅BR波动不能完全解释与意识相关的ERP的呼吸调节，而是需要由机械性OB刺激调节的大脑活动的同步。
