Data from: Dogs recognize dog and human emotions

The perception of emotional expressions allows animals to evaluate the social intentions and motivations of each other. This usually takes place within species; however, in the case of domestic dogs, it might be advantageous to recognize the emotions of humans as well as other dogs. In this sense, the combination of visual and auditory cues to categorize others' emotions facilitates the information processing and indicates high-level cognitive representations. Using a cross-modal preferential looking paradigm, we presented dogs with either human or dog faces with different emotional valences (happy/playful versus angry/aggressive) paired with a single vocalization from the same individual with either a positive or negative valence or Brownian noise. Dogs looked significantly longer at the face whose expression was congruent to the valence of vocalization, for both conspecifics and heterospecifics, an ability previously known only in humans. These results demonstrate that dogs can extract and integrate bimodal sensory emotional information, and discriminate between positive and negative emotions from both humans and dogs.

对情绪表情的感知能够帮助动物评估同类的社交意图与动机。此类感知通常仅发生于同一物种内部；但家养犬或许可通过识别人类与其他同类的情绪获得进化优势。就此而言，结合视觉与听觉线索对情绪对象进行分类，可促进信息处理过程，并体现出高水平的认知表征能力。本研究采用跨模态优先注视范式（cross-modal preferential looking paradigm），向受试家犬分别呈现带有不同情绪效价（愉悦/嬉戏型与愤怒/攻击型）的人类或犬类面部表情，并搭配来自同一发声个体的正性、负性发声或布朗噪声（Brownian noise）。实验结果显示，无论是面对同类还是异种个体，受试家犬注视与发声效价匹配的面部表情的时长均显著更长——此前仅人类被发现具备此类能力。上述结果表明，家犬能够提取并整合双模态感官情绪信息，并区分人类与同类所表达的正性与负性情绪。