https://phaidra.vetmeduni.ac.at/o:2111 Pupil size changes reveal dogs’ sensitivity to motion cues Völter, Christoph J. Christoph J. Völter 0000-0002-8368-7201 University of Veterinary Medicine Vienna Huber, Ludwig Ludwig Huber 0000-0002-0217-136X University of Veterinary Medicine Vienna Cell Press text eng Certain motion cues like self-propulsion and speed changes allow human and nonhuman animals to quickly detect animate beings. In the current eye-tracking study, we examined whether dogs' (Canis familiaris) pupil size was influenced by such motion cues. In Experiment 1, dogs watched different videos with normal or reversed playback direction showing a human agent releasing an object. The reversed playback gave the impression that the objects were self-propelled. In Experiment 2, dogs watched videos of a rolling ball that either moved at constant or variable speed. We found that the dogs' pupil size only changed significantly over the course of the videos in the conditions with self-propelled (upward) movements (Experiment 1) or variable speed (Experiment 2). Our findings suggest that dogs orient toward self-propelled stimuli that move at variable speed, which might contribute to their detection of animate beings. Biological Motion; Perception; Animacy; Agency; Speed; Attribution; Movement http://creativecommons.org/licenses/by/4.0/ https://phaidra.vetmeduni.ac.at/api/object/o:2111/download 10.1016/j.isci.2022.104801 https://phaidra.vetmeduni.ac.at/o:605 application/pdf iScience 25(9) (2022) iScience 25 9 1.97 MB 2022