When they were tested if they could perform without the rewards, the sheep were able to recognize the celebrities faces eight out of 10 times, Sky News reported. By the end of this experiment, the sheep chose a familiar celebrity's face over a stranger's face about 79 percent of the time on average.
Morton and a team trained eight sheep to recognise the famous faces from a frontal photo of each of them.
Morton and her team are now studying sheep that have been genetically modified to carry the gene mutation that causes Huntington's disease.
Jake Gyllenhaal, seen here with an animal that is not a sheep.
After some initial confusion, the animals picked the handler's picture in 72 percent of cases. Later, they were able to recognize the images for which they had been rewarded.
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Many other animals are known to recognise the faces among their own species, while some - including macaques, horses, dogs, mockingbirds, and sheep - can identify individuals from other species too.
"Our study gives us another way to monitor how these abilities change, particularly in sheep who carry the gene mutation that causes Huntington's disease", she pointed out.
The study feeds into ongoing research on treating neurodegenerative diseases such as Huntington's, in which face perception can be impaired. People recognise familiar faces easily, and can identify unfamiliar faces from repeatedly presented images.
"Sheep are long-lived and have brains that are similar in size and complexity to those of some monkeys".
In addition, they also say the study could help in the research into Huntington's disease, as well as other human brain disorders that affect mental processing.
"If this is the case, we can use the test to measure the beneficial effect of new treatments".