Proceedings of the Annual Meeting of the Cognitive Science Society

This study aimed to investigate whether people produce spontaneous co-speech gestures that reflect the underlying linguistic structures and additional information when speech is restricted by prompt phrases. Participants were asked to convey information about an animated movie using a three-word phrase in Japanese that could be interpreted in two different ways depending on their underlying deep structures. The animated movie included or did not include important information that was not described by the prompt phrases. The results showed that most participants produced gestures while uttering the phrase, and the onset of the nouns reflected the underlying linguistic structures. A time-series analysis revealed that the occurrence of object-action gestures that depicted a noun’s movement tended to reflect the associated linguistic structures. People spontaneously produce gestures, which may syntactically and semantically help to disambiguate ambiguous phrases.