Title: Influence of Turn-Taking in a Two-Person Conversation on the Gaze of a Viewer

In natural conversation, the minimal gaps and overlaps of the turns at talk indicate an accurate regulation of the timings of the turn-taking system. Here we studied how the turn-taking affects the gaze of a non-involved viewer of a two-person conversation. The subjects were presented with a video of a conversation while their eye gaze was tracked with an infrared camera. As a control, the video was presented without sound and the sound with still image of the speakers. Turns at talk directed the gaze behaviour of the viewers; the gaze followed, rather than predicted, the speakership change around the turn transition. Both visual and auditory cues presented alone also induced gaze shifts towards the speaking person, although significantly less and later than when the cues of both modalities were available. These results show that the organization of turn-taking has a strong influence on the gaze patterns of even non-involved viewers of the conversation, and that visual and auditory cues are in part redundant in guiding the viewers’ gaze. Citation: Hirvenkari L, Ruusuvuori J, Saarinen V-M, Kivioja M, Peräkylä A, et al. (2013) Influence of Turn-Taking in a Two-Person Conversation on the Gaze of a Viewer. PLoS ONE 8(8): e71569. doi:10.1371/journal.pone.0071569 Editor: Markus Lappe, University of Muenster, Germany Received July 10, 2012; Accepted July 8, 2013; Published August 12, 2013 Copyright: 2013 Hirvenkari et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This study was financially supported by the Academy of Finland (National Centers of Excellence Programme 2006–2011), European Union (NEST Programme PERCEPT, Perceptual Consciousness – Explication and Testing, 043261), UI-ART project of the TKK MIDE research programme (Finland), Jenny and Antti Wihuri Foundation and the ERC Advanced Grant (#232946). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: [email protected]