The Role of Visual Cues in the Comprehension of the Human Pointing Signals in Dogs
Abstract
In this study we examined the effect of the visually emphasized pointing arm in the case of the “Cross-forward pointing” gesture in dogs which proved to be difficult for them in an earlier study (Lakatos, Soproni, Dóka, & Miklósi, 2008). Our hypothesis was that if we emphasize the directionality of the visual cue using different, more contrasting coloured clothes during the tests, the dogs will be able to enhance their performance in two-way choice tasks. Our results showed that the conspicuousness of the pointing signal can affect how dogs perceive it. In contrast to our initial hypothesis pointing in a long white sleeve on a black background did not increase the dogs’ performance, while the black sleeves with nude (“white”) hands had an enhancing effect. This suggests that dogs need to see a salient body part what overhangs the median of the body silhouette and when the whole body is covered by black colour then the nude (pointing) hand appears as a conspicuous asymmetrical feature on one side of the body. Making the pointing hand less conspicuous makes the effect invariably disappear. Thus in summary we assume that the key aspect of the pointing gesture is not the directionality but the visually asymmetric cue provided by the human informant.