Multimodal evidence for predictive coding in sentence oral reading

Sentence oral reading requires not only a coordinated effort in the visual, articulatory, and cognitive processes but also supposes a top-down influence from linguistic knowledge onto the visual-motor behavior. Despite a gradual recognition of a predictive coding effect in this process, there is currently a lack of a comprehensive demonstration regarding the time-varying brain dynamics that underlines the oral reading strategy. To address this, our study used a multimodal approach, combining real-time recording of electroencephalography, eye movements, and speech, with a comprehensive examination of regional, inter-regional, sub-network, and whole-brain responses. Our study identified the top-down predictive effect with a phrase-grouping phenomenon in the fixation interval and eye-voice span. This effect was associated with the delta and theta band synchronization in the prefrontal, anterior temporal, and inferior frontal lobes. We also observed early activation of the cognitive control network and its recurrent interactions with the visual-motor networks structurally at the phrase rate. Finally, our study emphasizes the importance of cross-frequency coupling as a promising neural realization of hierarchical sentence structuring and calls for further investigation.