Data from: Do pet dogs (Canis familiaris) follow ostensive and non-ostensive human gaze to distant space and to objects?

Dogs are renowned for being skilful at using human-given communicative cues such as pointing. Results are contradictory, however, when it comes to dogs' following human gaze, probably due to methodological discrepancies. Here we investigated whether dogs follow human gaze to one of two food locations better than into distant space even after comparable pre-training. In Experiments 1 and 2, the gazing direction of dogs was recorded in a gaze-following into distant space and in an object-choice task where no choice was allowed, in order to allow a direct comparison between tasks, varying the ostensive nature of the gazes. We found that dogs only followed repeated ostensive human gaze into distant space, whereas they followed all gaze cues in the object-choice task. Dogs followed human gaze better in the object-choice task than when there was no obvious target to look at. In Experiment 3, dogs were tested in another object-choice task and were allowed to approach a container. Ostensive cues facilitated the dogs’ following gaze with gaze as well as their choices: we found that dogs in the ostensive group chose the indicated container at chance level, whereas they avoided this container in the non-ostensive group. We propose that dogs may perceive the object-choice task as a competition over food and may interpret non-ostensive gaze as an intentional cue that indicates the experimenter's interest in the food location she has looked at. Whether ostensive cues simply mitigate the competitive perception of this situation or they alter how dogs interpret communicative gaze needs further investigation. Our findings also show that following gaze with one's gaze and actually choosing one of the two containers in an object-choice task need to be considered as different variables. The present study clarifies a number of questions related to gaze-following in dogs and adds to a growing body of evidence showing that human ostensive cues can strongly modify dog behaviour.

犬类以擅长利用人类提供的指向类交际线索而广受认可。然而，关于犬类追随人类视线的相关研究结果却存在分歧，这一现象或源于实验方法学层面的差异。本研究旨在探究：即便经过标准化的预训练，犬类追随人类视线至两个食物位置之一的表现，是否优于追随视线至远处空间的表现。在实验1与实验2中，为实现不同注视提示的明示性（ostensive）差异下的两项任务的直接对比，我们分别在“视线追随至远处空间”范式与“不允许做出选择的物体选择任务”中记录了犬类的注视方向。结果显示，犬类仅会追随重复的人类明示性视线至远处空间，而在物体选择任务中则会追随所有类型的视线线索；相较于无明确注视目标的情境，犬类在物体选择任务中对人类视线的追随表现更佳。在实验3中，我们采用另一版物体选择任务对犬类进行测试，允许犬类靠近容器。结果表明，明示性线索（ostensive cue）不仅促进了犬类的视线追随行为，也提升了它们的选择表现：明示组犬类对提示容器的选择概率处于随机水平，而非明示组犬类则会避开该容器。我们推测，犬类可能将物体选择任务视为一场食物争夺竞争，并将非明示性视线解读为一种有意线索，该线索表明实验者对其注视过的食物位置存在兴趣。至于明示性线索究竟只是缓解了犬类对该情境的竞争感知，还是改变了犬类对交际性视线的解读方式，仍需进一步研究。本研究结果还表明，单纯的视线追随行为与物体选择任务中对两个容器之一的实际选择，应被视为两个不同的变量。本研究厘清了多个与犬类视线追随行为相关的问题，并为“人类明示性线索可显著改变犬类行为”这一论点补充了日益增多的实证依据。