National Post (National Edition)
One great leap for sheepkind
Cambridge U. flock recognizes celebrities
Of the roughly 1.1 billion sheep on Earth, roughly 1.1 billion have no idea who Barack Obama is. But there are at least eight sheep who can recognize the former U.S. president by his face. After a few days of training at the University of Cambridge in England, the animals learned to select the former president’s portrait out of a collection of photos.
Recognizing Obama meant the sheep won a snack. The scientists, in turn, were rewarded with better ways to measure sheep brain function.
Sheep are about as capable of recognizing faces as monkeys or humans, Cambridge researchers report. The Cambridge flock, eight female Welsh Mountain sheep, successfully learned the faces of four celebrities: Obama, British newscaster Fiona Bruce and actors Emma Watson and Jake Gyllenhaal.
“Sheep are capable of sophisticated decision-making,” said study author Jenny Morton, a neurobiologist at the University of Cambridge. Seven years ago, she said, she bought these sheep out of the back of a truck on its way to a slaughterhouse. Morton, who studies Huntington’s disease, uses them as a stand-in for humans, in part because “sheep have large brains with humanlike anatomy.”
The sheep learned to recognize human celebrities through three training scenarios. In each step, the sheep were presented with two options: a photo of the celebrity facing forward for the camera, or a photo of something else. The animals had 15 seconds to approach the celebrity image and trigger an infrared sensor. If the sheep chose correctly, the testing device popped out a treat.
The first test was the simplest. The sheep chose between a black screen or the celebrity face. The second round was slightly more challenging. Celebrity profile photos were randomly paired with images of one of 62 objects, all head-sized but lacking faces. (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.
“We chose the celebrities almost randomly,” Morton said. “I wanted people that the sheep had not met (I am very sure of this).”
Sheep, on average, chose the celebrity faces correctly in 8 out of 10 trials. That’s significantly better than the 50-per-cent rate the sheep would have shown if they were guessing haphazardly.
“I’m sure it will surprise other people, but to me this is all well known,” said Jonathan Peirce, who studies visual systems at the University of Nottingham. Peirce, who was not involved with this work, said this study is similar to work he and his colleagues conducted in 2001.
“My 2001 paper looked very carefully at this with a wider range of stimuli, more sheep and more conditions,” he said. “I guess they have extended our work to show that sheep generalize viewpoints of the faces, which does require a rich representation of the identity.”
During the training at Cambridge, the animals learned to recognize celebrities in forward-facing photos. In follow-up experiments, the authors of the new study had the sheep choose between images of celebrities or strangers. In these trials, though, the celebrity’s heads were tilted, beagle-like, at unfamiliar angles. They also wore different hairstyles. The sheep were less successful at identifying the tilted celebrities but still performed better than chance.