Initially, the sheep were trained to approach certain images by being given food rewards. "Our study gives us another way to monitor how these abilities change", Morton said. On her first try, one sheep appeared taken aback by the new face in the mix.
"Anyone who has spent time working with sheep will know that they are intelligent, individual animals who are able to recognize their handlers", said Professor Jenny Morton, who led the Cambridge study.
The study was done by Cambridge University researchers, who said that they were able to train sheep to recognise faces of actors Jake Gyllenhaal and Emma Watson, former US President Barack Obama and BBC newsreader Fiona Bruce. "Although I didn't think sheep could recognize emotion, it made me think about face recognition as a complex brain process". "Either the human face is similar enough to the sheep face that [it] activates the sheep face-processing system, or human-face recognition relies on more general-purpose recognition systems".
The sheep were less successful at identifying the tilted celebrities but still performed better than chance. (A sheep might have had to select Emma Watson vs. a football helmet or gas lamp, for instance.) The third test pitted the sheep's celebrity targets against unfamiliar humans.More news: Veterans in Congress speak out against invading North Korea
In addition to being shown images of the celebrities facing forward, scientists also tested the animals' ability to recognise the faces in photographs taken from other angles. Training involved the sheep making decisions as they moved around a specially-designed pen.
In a specially equipped pen, sheep were shown pictures of people on two computer screens. Maybe they just didn't like that the non-familiar lacked a reward, for example. Eight times out 10 the sheep picked the celebrity. That's what scientists discovered through testing sheep by showing them celebrity portraits.
As expected, the sheep's performance dropped, but only by about 15 per cent - a figure comparable to that seen when humans perform the task.
Researchers say this is without any prior training. The sheep chose the right face eight out of 10 times.