Facial recognition is a complex task which requires as many as 200 neurons in the brain’s temporal lobe, called “face patches,” to fire up simultaneously within milliseconds. Hence the skill has always been believed to be the realm of “intelligent” animals such as humans, monkeys, apes, dogs, and horses. Now, British scientists have found that the unassuming cud-chewing sheep also possess this skill.
Jennifer Morton, a neurobiologist at the University of Cambridge who led the study, says the team picked sheep because the social animals communicate with each other in a number of ways, one of which they suspected was by facial recognition. The four randomly selected celebrities to test the farm animal’s identification prowess were — “Harry Potter” actress Emma Watson, American actor Jake Gyllenhaal, British television journalist Fiona Bruce, and former US President Barack Obama. The researchers picked famous personalities for their experiment because it was easy to find photos taken at different angles.
The eight sheep, selected from the university's flock, were trained for the task with the help of two computer screens. One projected a celebrity photo, while the other showcased a black screen or a random object. Each time the sheep chose the correct image by breaking the infrared beam with its nose, it received a food pellet. Wrong identification resulted in a loud buzzer and no treat.
Once the animals were familiar with the four celebrities, they were put to the test. This time, both screens featured photos, one of the star and the other of a random person. The researchers found that the sheep were right 75 percent of the time. Though impressive, it was not enough to conclude if the animals actually recognized the faces or just had good memories. To ensure it was the former, the sheep were exposed to the four celebrities again. This time, the photos, taken from a different angle, showed their faces tilted. Though the success rate was a slightly lower 66 percent, it was enough to prove the sheep’s facial recognition abilities.
For the final trial, the researchers projected a photo of the animals’ handler, who they see for at least two hours a day, alongside one of a random person. Sure enough, most of the sheep picked the handler. One appeared a little confused and went back and forth between the two, before finally settling for the right image. Their ability to identify a 2D photo of a 3D human with no previous training was ultimate proof that sheep have facial recognition capabilities.
Brad Duchaine, a Dartmouth brain scientist, is not surprised at the study’s results which were published in the Royal Society Open Science on November 8. The expert says, “My guess is that the ability of sheep to recognize human faces is a by-product of selection to discriminate between different sheep faces. 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.”
While knowing that sheep don’t just blindly follow people is enlightening, there is a more important purpose for Morton’s study. The researcher hopes that understanding how the sheep’s brain works will give her insight into Huntington’s disease. People suffering from this rare, but incurable, affliction also have a hard time recognizing faces. She next plans to study and treat a flock of sheep from Australia that has been genetically modified to carry the gene for Huntington’s disease. The researcher believes that if we find a cure for the sheep, we will one day be able to do the same for humans. The big question now is — can humans discriminate between sheep faces?
Resources: royalsocietypublishing.org, BBC.co.uk,motherboard.vice.com