Neural oscillations are thought to support speech and language processing. They may not only inherit acoustic rhythms, but might also impose endogenous rhythms onto processing. In support of this, we here report that human (both male and female) eye movements during naturalistic reading exhibit rhythmic patterns that show frequency-selective coherence with the EEG, in the absence of any stimulation rhythm. Periodicity was observed in two distinct frequency bands: First, word-locked saccades at 4-5 Hz display coherence with whole-head theta-band activity. Second, fixation durations fluctuate rhythmically at ~1 Hz, in coherence with occipital delta-band activity. This latter effect was additionally phase-locked to sentence endings, suggesting a relationship with the formation of multi-word chunks. Together, eye movements during reading contain rhythmic patterns that occur in synchrony with oscillatory brain activity. This suggests that linguistic processing imposes preferred processing time scales onto reading, largely independent of actual physical rhythms in the stimulus.

SIGNIFICANCE STATEMENT The sampling, grouping, and transmission of information are supported by rhythmic brain activity, so-called neural oscillations. In addition to sampling external stimuli, such rhythms may also be endogenous, affecting processing from the inside out. In particular, endogenous rhythms may impose their pace onto language processing. Studying this is challenging because speech contains physical rhythms that mask endogenous activity. To overcome this challenge, we turned to naturalistic reading, where text does not require the reader to sample in a specific rhythm. We observed rhythmic patterns of eye movements that are synchronized to brain activity as recorded with EEG. This rhythmicity is not imposed by the external stimulus, which indicates that rhythmic brain activity may serve as a pacemaker for language processing.

神经振荡被认为支持语音和语言处理。它们不仅可能继承声学节律，还可能将内源节律强加于处理过程中。为了支持这一点，我们在这里报告，在没有任何刺激节奏的情况下，自然阅读过程中人类（男性和女性）的眼球运动表现出节奏模式，显示出与脑电图的频率选择性一致性。在两个不同的频带中观察到周期性：首先，4-5 Hz 的字锁定扫视显示出与全头 θ 频带活动的一致性。其次，注视持续时间以约 1 Hz 有节奏地波动，与枕骨 Delta 带活动一致。后一种效应还与句子结尾相锁定，表明与多词块的形成有关。一起，阅读过程中的眼球运动包含与大脑振荡活动同步发生的节奏模式。这表明语言处理将首选的处理时间尺度强加于阅读，很大程度上独立于刺激中的实际身体节奏。

意义声明信息的采样、分组和传输是由有节奏的大脑活动（即所谓的神经振荡）支持的。除了采样外部刺激之外，这种节律也可能是内源性的，从内到外影响处理。特别是，内源节奏可能会将其节奏强加于语言处理。研究这一点具有挑战性，因为言语包含掩盖内源活动的身体节奏。为了克服这一挑战，我们转向自然主义阅读，其中文本不需要读者以特定的节奏进行采样。我们观察到眼球运动的节律模式与脑电图记录的大脑活动同步。这种节律性不是由外部刺激强加的，这表明有节律的大脑活动可能充当语言处理的起搏器。