Abstract: Numerical competence has been demonstrated in a wide range of animal species. The level of numerical abilities shown ranges from simple relative numerousness judgements to true counting. In this study we used the preferential looking technique to test whether 11 pet dogs could count. The dogs were presented with three simple calculations: “1+1=2”; “1+1=1”; and “1+1=3”. These calculations were performed by presenting the dogs with treats that were placed behind a screen that allowed manipulation of the outcome of the calculation. When the dogs expected the outcome they spent the same amount of time looking at the result of the calculation as they did on the initial presentation. However, when the result was unexpected dogs spent significantly longer looking at the outcome of the calculation. The results suggest that the dogs were anticipating the outcome of the calculations they observed, thus suggesting that dogs may have a rudimentary ability to count.

Abstract: Abstract  We tested whether dogs have a cross-modal representation of human individuals. We presented domestic dogs with a photo of either the owner's or a stranger's face on the LCD monitor after playing back a voice of one of those persons. A voice and a face matched in half of the trials (Congruent condition) and mismatched in the other half (Incongruent condition). If our subjects activate visual images of the voice, their expectation would be contradicted in Incongruent condition. It would result in the subjects` longer looking times in Incongruent condition than in Congruent condition. Our subject dogs looked longer at the visual stimulus in Incongruent condition than in Congruent condition. This suggests that dogs actively generate their internal representation of the owner's face when they hear the owner calling them. This is the first demonstration that nonhuman animals do not merely associate auditory and visual stimuli but also actively generate a visual image from auditory information. Furthermore, our subject also looked at the visual stimulus longer in Incongruent condition in which the owner's face followed an unfamiliar person's voice than in Congruent condition in which the owner's face followed the owner's voice. Generating a particular visual image in response to an unfamiliar voice should be difficult, and any expected images from the voice ought to be more obscure or less well defined than that of the owners. However, our subjects looked longer at the owner's face in Incongruent condition than in Congruent condition. This may indicate that dogs may have predicted that it should not be the owner when they heard the unfamiliar person's voice.

Abstract: Abstract  When apes are not fully understood by humans, they persist with attempts to communicate, elaborating their behaviours to better convey their meaning. Such abilities have never been investigated in dogs. The present study aimed to clarify any effect of the visual attentional state of the owner on dogs’ (Canis familiaris) social-communicative signals for interacting with humans, and to determine whether dogs persist and elaborate their behaviour in the face of failure to communicate a request. Gaze at a hidden target or at the owner, gaze alternation between a hidden target and the owner, vocalisations and contacts in 12 guide and 12 pet dogs were analysed (i) when the dogs were asked by their owners (blind or sighted) to fetch their inaccessible toy and (ii) when the dogs were subsequently given an unfamiliar object (apparent unsuccessful communication) or their toy (apparent successful communication). No group differences were found, indicating no effect of the visual status of the owner on the dogs’ socio-communicative modes (i.e. no sensitivity to human visual attention). Results, however, suggest that the dogs exhibited persistence (but not elaboration) in their “showing” behaviours in each condition, except that in which the toy was returned. Thus, their communication was about a specific item in space (the toy). The results suggest that dogs possess partially intentional non-verbal deictic abilities: (i) to get their inaccessible toy, the dogs gazed at their owners as if to trigger their attention; gaze alternation between the owner and the target direction, and two behaviours directed at the target were performed, apparently to indicate the location of the hidden toy; (ii) after the delivery of the toy, the dogs behaved as if they returned to the play routine, gazing at their owner whilst holding their toy. In conclusion, this study shows that dogs possess partially intentional non-verbal deictic abilities: they exhibit successive visual orienting between a partner and objects, apparent attention-getting behaviours, no sensitivity to the visual status of humans for communication, and persistence in (but no elaboration of) communicative behaviours when apparent attempts to “manipulate” the human partner fail.

Abstract: ven young humans show sensitivity to the accuracy and reliability of informants’ reports. Children are selective in soliciting information and in accepting claims. Recent research has also investigated domestic dogs’ (Canis familiaris) sensitivity to agreement among human informants. Such research utilizing a common human pointing gesture to which dogs are sensitive in a food retrieval paradigm suggests that dogs might choose among informants according to the number of points exhibited, rather than the number of individuals indicating a particular location. Here, we further investigated dogs’ use of information from human informants using a stationary pointing gesture, as well as the conditions under which dogs would utilize a stationary point. First, we explored whether the number of points or the number of individuals more strongly influenced dogs’ choices. To this end, dogs encountered a choice situation in which the number of points exhibited toward a particular location and the number of individuals exhibiting those points conflicted. Results indicated that dogs chose in accordance with the number of points exhibited toward a particular location. In a second experiment, we explored the possibility that previously learned associations drove dogs’ responses to the stationary pointing gesture. In this experiment, dogs encountered a choice situation in which artificial hands exhibited a stationary pointing gesture toward or away from choice locations in the absence of humans. Dogs chose the location to which the artificial hand pointed. These results are consistent with the notion that dogs may respond to a human pointing gesture due to their past-learning history.

Abstract: Dogs are known to consistently follow human pointing gestures. In this study, we asked whether dogs “automatically” do this or whether they flexibly adjust their behavior depending upon the reliability of the pointer, demonstrated in an immediately preceding event. We tested pet dogs in a version of the object choice task in which a piece of food was hidden in one of the two containers. In Experiment 1, Phase 1, an experimenter pointed at the baited container; the second container was empty. In Phase 2, after showing the contents of both containers to the dogs, the experimenter pointed at the empty container. In Phase 3, the procedure was exactly as in Phase 1. We compared the dogs’ responses to the experimenter’s pointing gestures in Phases 1 and 3. Most dogs followed pointing in Phase 1, but many fewer did so in Phase 3. In Experiment 2, dogs followed a new experimenter’s pointing in Phase 3 following replication of procedures of Phases 1 and 2 in Experiment 1. This ruled out the possibility that dogs simply lost motivation to participate in the task in later phases. These results suggest that not only dogs are highly skilled at understanding human pointing gestures, but also they make inferences about the reliability of a human who presents cues and consequently modify their behavior flexibly depending on the inference.