Smith Amy Victoria, Proops Leanne, Grounds Kate, Wathan Jennifer, McComb Karen
Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Brighton BN1 9QH, UK
Mammal Vocal Communication and Cognition Research Group, School of Psychology, University of Sussex, Brighton BN1 9QH, UK.
Biol Lett. 2016 Feb;12(2):20150907. doi: 10.1098/rsbl.2015.0907.
Whether non-human animals can recognize human signals, including emotions, has both scientific and applied importance, and is particularly relevant for domesticated species. This study presents the first evidence of horses' abilities to spontaneously discriminate between positive (happy) and negative (angry) human facial expressions in photographs. Our results showed that the angry faces induced responses indicative of a functional understanding of the stimuli: horses displayed a left-gaze bias (a lateralization generally associated with stimuli perceived as negative) and a quicker increase in heart rate (HR) towards these photographs. Such lateralized responses towards human emotion have previously only been documented in dogs, and effects of facial expressions on HR have not been shown in any heterospecific studies. Alongside the insights that these findings provide into interspecific communication, they raise interesting questions about the generality and adaptiveness of emotional expression and perception across species.
非人类动物是否能够识别包括情感在内的人类信号，这既具有科学重要性，也具有应用重要性，尤其对于家养物种而言。本研究首次证明了马能够自发区分照片中人类的正面（开心）和负面（愤怒）面部表情。我们的结果表明，愤怒的面孔引发了表明对刺激有功能性理解的反应：马表现出向左凝视偏向（一种通常与被视为负面的刺激相关的偏侧化），并且对这些照片的心率（HR）上升更快。此前，这种对人类情感的偏侧化反应仅在狗身上有记录，而且在任何异种研究中都未表明面部表情对心率的影响。除了这些发现为种间交流提供的见解之外，它们还引发了关于跨物种情感表达和感知的普遍性及适应性的有趣问题。
