Gesture Influences Resolution of Ambiguous Statements of Neutral and Moral Preferences.

When faced with an ambiguous pronoun, comprehenders use both multimodal cues (e.g., gestures) and linguistic cues to identify the antecedent. While research has shown that gestures facilitate language comprehension, improve reference tracking, and influence the interpretation of ambiguous pronouns, literature on reference resolution suggests that a wide set of linguistic constraints influences the successful resolution of ambiguous pronouns and that linguistic cues are more powerful than some multimodal cues. To address the outstanding question of the importance of gesture as a cue in reference resolution relative to cues in the speech signal, we have previously investigated the comprehension of contrastive gestures that indexed abstract referents - in this case expressions of personal preference - and found that such gestures did facilitate the resolution of ambiguous statements of preference. In this study, we extend this work to investigate whether the effect of gesture on resolution is diminished when the gesture indexes a statement that is less likely to be interpreted as the correct referent. Participants watched videos in which a speaker contrasted two ideas that were either neutral (e.g., whether to take the train to a ballgame or drive) or moral (e.g., human cloning is (un)acceptable). A gesture to the left or right side co-occurred with speech expressing each position. In gesture-disambiguating trials, an ambiguous phrase (e.g., I agree with that, where that is ambiguous) was accompanied by a gesture to one side or the other. In gesture non-disambiguating trials, no third gesture occurred with the ambiguous phrase. Participants were more likely to choose the idea accompanied by gesture as the stimulus speaker's preference. We found no effect of scenario type. Regardless of whether the linguistic cue expressed a view that was morally charged or neutral, observers used gesture to understand the speaker's opinion. This finding contributes to our understanding of the strength and range of cues, both linguistic and multimodal, that listeners use to resolve ambiguous references.