Abstract
A framework for discussing the neural underpinning of communication processes is proposed from the perspective of synchronization. This framework comprises four stages: (i) characterizing the target communication in a two-dimensional space defined by symbolic/embodied (non-symbolic) and voluntary/involuntary processes, (ii) focusing on the level of analysis of synchrony on an ontological hierarchy, (iii) constructing a neurocognitive model to simulate neural dynamics, and (iv) testing an empirical hypothesis on the neural underpinning of communication through model-based electroencephalography (EEG) connectivity neurofeedback in communication experiments with the cognitive neural mass/field model. We performed two EEG experiments, implementing the former two stages: the formation of symbolic communication, in which communication changed from voluntary to involuntary, and intentional switching in embodied communication, which involves switching between voluntary and involuntary behavior. The findings on communicative brain activities from these experiments culminated in the hypothesis that three brain regions are involved in interpreting symbols and motor intentions as well as in social coordination, in which one region might be shared by two modalities and the other two are specific to each modality. As we could perform the experiments and their analyses and derive a working hypothesis based on the framework, we claim that the proposed framework may be vital for investigating the neural underpinnings of communication in two different modalities in a unified manner.
https://ror.org/03frj4r98 
