Local Dot Motion, Not Global Configuration, Determines Dogs’ Preference for Point-Light Displays
Laboratory of Applied Ethology, Department of Comparative Biomedicine and Food Science, University of Padua, Viale dell’Università 16, 35020 Legnaro, Italy
Department of General Psychology, University of Padua, Via Venezia 8, 35131 Padova, Italy
Author to whom correspondence should be addressed.
Received: 26 July 2019 / Revised: 27 August 2019 / Accepted: 3 September 2019 / Published: 6 September 2019
Animal motion is characterised by predictable kinematics according to their body morphology and the laws of gravity. This pattern of movement, called biological motion, is traditionally studied using animated displays created by placing a small number of light dots on the major joints of living beings. Previous studies have shown that several animal species can reliably discriminate dot displays depicting an animal walking, and their performance is impeded when the display is turned upside-down and is variably affected when each dot is displaced to disrupt the global biological arrangement. In this study, we investigated this phenomenon in dogs during the presentation of dot displays depicting humans or dogs walking. Our findings showed that dogs preferred to view the display which depicted an upright dog, regardless of its global arrangement, and had no significant preferences when displays depicting humans were presented. This suggests that dogs’ sensitivity to biological motion depends mainly on the presence of dot motion that moves in accordance with gravity. Also, our findings suggest that, despite dogs’ extensive exposure to human motion, they are not sensitive to the bipedal motion presented in the human dot displays.