At any given moment our sensory systems receive multiple, often rhythmic, inputs from the environment. Processing of temporally structured events in one sensory modality can guide both behavioral and neural processing of events in other sensory modalities, but whether this occurs remains unclear. Here, we used human electroencephalography (EEG) to test the cross-modal influences of a continuous auditory frequency-modulated (FM) sound on visual perception and visual cortical activity. We report systematic fluctuations in perceptual discrimination of brief visual stimuli in line with the phase of the FM-sound. We further show that this rhythmic modulation in visual perception is related to an accompanying rhythmic modulation of neural activity recorded over visual areas. Importantly, in our task, perceptual and neural visual modulations occurred without any abrupt and salient onsets in the energy of the auditory stimulation and without any rhythmic structure in the visual stimulus. As such, the results provide a critical validation for the existence and functional role of cross-modal entrainment and demonstrates its utility for organizing the perception of multisensory stimulation in the natural environment.

SIGNIFICANCE STATEMENT Our sensory environment is filled with rhythmic structures that are often multi-sensory in nature. Here, we show that the alignment of neural activity to the phase of an auditory frequency-modulated (FM) sound has cross-modal consequences for vision: yielding systematic fluctuations in perceptual discrimination of brief visual stimuli that are mediated by accompanying rhythmic modulation of neural activity recorded over visual areas. These cross-modal effects on visual neural activity and perception occurred without any abrupt and salient onsets in the energy of the auditory stimulation and without any rhythmic structure in the visual stimulus. The current work shows that continuous auditory fluctuations in the natural environment can provide a pacing signal for neural activity and perception across the senses.

在任何特定时刻，我们的感觉系统都会接收来自环境的多种（通常是有节奏的）输入。一种感觉方式中的时间结构事件的处理可以指导其他感觉方式中的事件的行为和神经处理，但这种情况是否发生仍不清楚。在这里，我们使用人类脑电图（EEG）来测试连续听觉调频（FM）声音对视觉感知和视觉皮层活动的跨模式影响。我们报告了与 FM 声音相位一致的短暂视觉刺激的知觉辨别的系统波动。我们进一步表明，视觉感知的这种节律性调节与视觉区域记录的神经活动的伴随节律性调节有关。重要的是，在我们的任务中，感知和神经视觉调制发生时，听觉刺激的能量没有任何突然和显着的起始，并且视觉刺激中没有任何节奏结构。因此，结果为跨模式夹带的存在和功能作用提供了关键验证，并证明了其在组织自然环境中多感官刺激的感知方面的实用性。

意义陈述我们的感官环境充满了节奏结构，这些结构本质上通常是多感官的。在这里，我们表明，神经活动与听觉调频（FM）声音的相位的对齐对视觉具有跨模式的影响：在短暂视觉刺激的知觉辨别中产生系统波动，这些波动是由伴随的神经节律调制介导的。记录视觉区域的活动。这些对视觉神经活动和感知的跨模式效应的发生，在听觉刺激的能量中没有任何突然和显着的起始，并且在视觉刺激中没有任何节律结构。目前的工作表明，自然环境中的持续听觉波动可以为神经活动和感官感知提供节奏信号。