When dogs seem to lose their nose:: an investigation on the use of visual and olfactory cues in communicative context between dog and owner

In two experimental studies, we observed whether dogs rely on olfactory and/or visual information about the hiding place for food in a two-choice test. However, for some dogs direct olfactory (smelling the food) or visual (observing of the food being hidden) experience has been contradicted by human pointing (a well-known communicative gesture for the dog) to the 'incorrect' hiding place. We have found that dogs were able to use both olfactory and visual cues efficiently to choose above chance in a choice situation when there was no human cueing. However, in other experimental groups the dogs tended to choose the bowl pointed at by the human. This change in their behavior was more pronounced if they had only olfactory information about the location of the food. In contrast, if they had seen where the food was placed, dogs were more reluctant to follow the pointing gesture, but even so their performance worsened compared to the case in which they saw only the bowl baited. These results give further support for the hypothesis that dogs regard the pointing gesture as being a communicative act about the placing of the food, but they do not rely on this gesture blindly and they can modify their behavior based on visual experience related directly to the hiding of the food. Further, contrary to general expectations dogs rely in this situation, only to some degree on olfactory cues. (C) 2003 Elsevier Science B.V. All rights reserved.