Abstract:
Temporal prediction assists language comprehension. In a series of recent behavioral studies, we have shown that listeners specifically employ rhythmic modulations of prosody to estimate the duration of upcoming sentences, thereby speeding up comprehension. In the current human magnetoencephalography (MEG) study on participants of either sex, we show that the human brain achieves this function through a mechanism termed entrainment. Through entrainment, electrophysiological brain activity maintains and continues contextual rhythms beyond their offset. Our experiment combined exposure to repetitive prosodic contours with the subsequent presentation of visual sentences that either matched or mismatched the duration of the preceding contour. During exposure to prosodic contours, we observed MEG coherence with the contours, which was source-localized to right-hemispheric auditory areas. During the processing of the visual targets, activity at the frequency of the preceding contour was still detectable in the MEG; yet sources shifted to the (left) frontal cortex, in line with a functional inheritance of the rhythmic acoustic context for prediction. Strikingly, when the target sentence was shorter than expected from the preceding contour, an omission response appeared in the evoked potential record. We conclude that prosodic entrainment is a functional mechanism of temporal prediction in language comprehension. In general, acoustic rhythms appear to endow language for employing the brain\'s electrophysiological mechanisms of temporal prediction.
摘要:
时间预测有助于语言理解。在最近的一系列行为研究中,我们已经证明,听众特别使用韵律的节奏调制来估计即将到来的句子的持续时间,从而加快理解。在当前对任何性别参与者的人类脑磁图(MEG)研究中,我们证明了人脑是通过一种叫做夹带的机制来实现这一功能的。通过夹带,电生理大脑活动维持并继续超出其偏移量的上下文节律。我们的实验将重复的韵律轮廓与随后的视觉句子的呈现相结合,这些句子与先前轮廓的持续时间相匹配或不匹配。在暴露于韵律轮廓期间,我们观察到MEG与轮廓的相干性,它位于右半球的听觉区域。在视觉目标的处理过程中,在MEG中仍然可以检测到先前轮廓频率的活动;然而源转移到(左)额叶皮层,符合用于预测的节奏声学上下文的功能继承。引人注目的是,当目标句子比先前轮廓的预期短时,在诱发电位记录中出现遗漏反应。我们得出的结论是,韵律夹带是语言理解中时间预测的功能机制。总的来说,声学节律似乎赋予语言以利用大脑的时间预测的电生理机制。重要性陈述语言理解受益于我们预测即将到来的刺激的能力。这里,我们报告了一个关键的神经基质。我们表明,电生理大脑活动从先前的上下文继承了韵律调制-语音的旋律,允许听众估计即将到来的语言刺激的持续时间:通过使用脑磁图,我们发现大脑不仅在说话时对韵律有反应,但它的活动以韵律频率持续到未来几秒钟,有利于行为反应。在延续期间,活动从听觉转移到额叶皮层,大脑预测能力的中心。人脑似乎通过复制感官节奏并将其投射到未来来启动对语言刺激的自上而下的预测。