In this paper, we investigate the linguistic factors affecting production of gestures in discourse by using Japanese three-party conversation corpus. We develop statistical models that best predict the occurrence, and the viewpoint, of gestures in the corpus based on syntactic factors such as zero pronouns, person, onomatopoeia, and verb types as well as discourse factors such as backward-looking centers, preferred centers, and center-transition patterns. We show that not only syntactic but also discourse factors influence the occurrence of gestures, suggestingthat gesture production is affected by mental imagery at the level of utterance as well as discourse. We also show that the viewpoint of gestures, by contract, is affected only by syntactic factors, suggesting that different kinds of linguistic factors are involved in different aspects of gesture production.
