Head and Body Cues Guide Eye Movements and Facilitate Target Search in Real- Word Videos

Static gaze cues presented in central vision result in observer shifts of covert attention and eye movements, and benefits in perceptual performance in the detection of simple targets. Less is known about how dynamic gazer behaviors with head and body motion influence search eye movements and performance in more ecological perceptual tasks in real-world scenes. Participants searched for a target person (yes/no task, 50% presence) while watching videos of one to three gazers looking at a designated person (50 % valid gaze cue, looking at the target). We digitally manipulated videos to create three conditions of gazers: floating heads (only head movements), headless bodies, and the baseline intact. We show that valid dynamic gaze cues guided participants’ eye movements (up to 3 fixations) closer to the target, shortened the times to fixate within 2° of the target, reduced fixations to the gazers, and improved target detection. Gaze cue guidance was smallest when the gazer’s head was removed from the videos. Separate judgments estimating gaze showed that the reduced eye movement guidance from lower body cueing is related to observers’ difficulty extracting gaze information without the presence of the head. Together, the study extends previous work by evaluating the impact of ecologically relevant dynamic gazer behaviors on search with realistic cluttered videos.