Sheep Can Recognize Human Faces from Two-Dimensional Images

Sheep can be trained to recognize human faces from photographic portraits - and can even identify the picture of their handler without prior training - according to new research from scientists at the University of Cambridge (UK). The study, published online on November 8, 2017 in Royal Society: Open Science, is part a series of tests given to the sheep to monitor their cognitive abilities. The open-access article is titled “Sheep Recognize Familiar and Unfamiliar Human Faces from Two-Dimensional Images.” Because of the relatively large size of their brains and their longevity, sheep are a good animal model for studying neurodegenerative disorders such as Huntington's disease. The ability to recognize faces is one of the most important human social skills. We recognize familiar faces easily, and can identify unfamiliar faces from repeatedly presented images. As with some other animals such as dogs and monkeys, sheep are social animals that can recognize other sheep as well as familiar humans. Little is known, however, about their overall ability to process faces. Researchers from the University of Cambridge's Department of Physiology, Development, and Neuroscience trained eight sheep to recognize the faces of four celebrities from photographic portraits displayed on computer screens. The celebrities were Fiona Bruce, Jake Gyllenhaal, Barack Obama, and Emma Watson. Training involved the sheep making decisions as they moved around a specially-designed pen. At one end of the pen, they would see two photographs displayed on two computer screens and would receive a reward of food for choosing the photograph of the celebrity (by breaking an infrared beam near the screen); if they chose the wrong photograph, a buzzer would sound and they would receive no reward. Over time, they learn to associate a reward with the celebrity's photograph. After training, the sheep were shown two photographs - the celebrity's face and another face. In this test, sheep correctly chose the learned celebrity face eight times out of ten.