Nawroth Christian, Martin Zoe M, McElligott Alan G
Institute of Behavioural Physiology, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.
Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.
Front Psychol. 2020 May 19;11:915. doi: 10.3389/fpsyg.2020.00915. eCollection 2020.
Dogs () are extremely adept in interpreting human-given cues, such as the pointing gesture. However, the underlying mechanisms on how domestic non-companion species use these cues are not well understood. We investigated the use of human-given pointing gestures by goats () in an object choice task, where an experimenter surreptitiously hid food in one of two buckets. Subjects first had to pass a pre-test where the experimenter indicated the location of the food to the subject by a proximal pointing gesture. Subjects that succeeded in the use of this gesture were transferred to the actual test. In these subsequent test trials, the experimenter indicated the location of the food to the subject by using three different pointing gestures: proximal pointing from a middle position (distance between target and index finger: 30 cm), crossed pointing from the middle position (distance between target and index finger: 40 cm), asymmetric pointing from the position of the non-baited bucket (distance between target and index finger: 90 cm). Goats succeeded in the pointing gestures that presented an element of proximity (proximal and crossed) compared to when the experimenter was further away from the rewarded location (asymmetric). This indicates that goats can generalize their use of the human pointing gesture but might rely on stimulus/local enhancement rather than referential information. In addition, goats did not improve their responses over time, indicating that no learning took place. The results provide a greater understanding of human-animal interactions and social-cognitive abilities of farm animals, which allows for the provision of enhanced management practices and welfare conditions.
狗在解读人类给出的线索（如指示手势）方面极其熟练。然而，对于家养的非伴侣动物如何利用这些线索的潜在机制，我们还了解得不够透彻。我们在一项物体选择任务中研究了山羊对人类指示手势的运用，在该任务中，一名实验者偷偷地将食物藏在两个桶中的一个里。受试者首先要通过一个预测试，在预测试中实验者通过近距离指示手势向受试者表明食物的位置。成功运用该手势的受试者被转入实际测试。在随后的这些测试试验中，实验者通过使用三种不同的指示手势向受试者表明食物的位置：从中间位置进行近距离指示（目标与食指之间的距离：30厘米）、从中间位置进行交叉指示（目标与食指之间的距离：40厘米）、从不放诱饵的桶的位置进行不对称指示（目标与食指之间的距离：90厘米）。与实验者离奖励位置较远时（不对称指示）相比，山羊在呈现出接近元素的指示手势（近距离和交叉指示）上表现成功。这表明山羊能够推广它们对人类指示手势的运用，但可能依赖于刺激/局部增强而非参照信息。此外，山羊并没有随着时间的推移而改善它们的反应，这表明没有发生学习。这些结果让我们对人类与动物的互动以及农场动物的社会认知能力有了更深入的了解，从而有助于提供更好的管理方法和福利条件。
