Speakers' eye gaze disambiguates referring expressions early during face-to-face conversation

In two experiments, we explored the time course and flexibility with which speakers' eye gaze can be used to disambiguate referring expressions in spontaneous dialog. Naive director/matcher pairs were separated by a barrier and saw each other's faces but not their displays. Displays held identical objects, with the matcher's arranged in a row and the director's mirroring the matcher's or else in a circle (Experiment 1) or in a reversed row (Experiment 2). Directors instructed matchers to move targets, which were unique or had a competitor nearby or far away. When mirrored displays held far competitors, matchers used directors' eye gaze to identify targets before the linguistic point of disambiguation. Reversed displays caused substantial competition, yet matchers still identified targets before the linguistic point of disambiguation, showing an ability to rapidly re-map directors' eye gaze. Our findings indicate eye gaze is a powerful and flexible disambiguating cue in referential communication.