A cognitive architecture for the coordination of utterances

Dialog partners coordinate with each other to reach a common goal. The analogy with other joint activities has sparked interesting observations (e.g., about the norms governing turn-taking) and has informed studies of linguistic alignment in dialog. However, the parallels between language and action have not been fully explored, especially with regard to the mechanisms that support moment-by-moment coordination during language use in conversation. We review the literature on joint actions to show (i) what sorts of mechanisms allow coordination and (ii) which types of experimental paradigms can be informative of the nature of such mechanisms. Regarding (i), there is converging evidence that the actions of others can be represented in the same format as one's own actions. Furthermore, the predicted actions of others are taken into account in the planning of one's own actions. Similarly, we propose that interlocutors are able to coordinate their acts of production because they can represent their partner's utterances. They can then use these representations to build predictions, which they take into account when planning self-generated utterances. Regarding (ii), we propose a new methodology to study interactive language. Psycholinguistic tasks that have traditionally been used to study individual language production are distributed across two participants, who either produce two utterances simultaneously or complete each other's utterances.