The cognitive architecture and function of co-speech gesture has been the subject of a large body of research. We investigate two main questions in this field, namely, whether language and gesture are the same or two inter-related systems, and whether gestures help resolve speech problems, by examining the relationship between gesture and disfluency in neurotypical speakers. Our results support the view of separate, but inter- related systems by showing that speech problems do not necessarily cause gesture problems, and on many occasions, gestures signal an upcoming speech problem even before it surfaces in overt speech. We also show that while gestures are more common on fluent trials, speakers use both iconic and beat gestures on disfluent trials to facilitate communication, although the two gesture types support communication in different ways.

How do people conceptualize motion events and talk about them? The current study examines how gestural representations of motion events arise from linguistic expressions in Persian, which has characteristics of both Talmy’s satellite- and verb-framed languages. We examined native Persian speakers’ speech and gestures in describing 20 motion events. We focused on two motion event components: path (trajectory of motion like up) and manner (how the action is performed like jumping). Results indicated that when expressing motion, Persian speakers produced path in both speech and gesture, whereas manner was conveyed only through speech (mostly as adverbs). Additionally, dynamic gestures tended to occur in the same order they were uttered. The difference between path and manner findings asks for further research to examine language-gesture interaction in detail among different languages. Results also suggest refinement in gesture theories that argue for one-to-one correspondence between speech and gesture.