More and more, computers are showing their superiority over humans in a multitude of tasks. A new study reveals that a computer system is able to detect – with better accuracy than a human – whether our expressions of pain are genuine or phony.

The researchers, from the University of California-San Diego (UCSD) and the University of Toronto in Canada, have published their findings in the journal Current Biology.

They note that in social species like humans, faces have evolved to show valuable information in social contexts, and this includes expressions of emotions and pain.

However, “humans can simulate facial expressions and fake emotions well enough to deceive most observers,” says Prof. Kang Lee, senior author from the University of Toronto.

According to the study, there are two motor pathways in the brain that control facial movement:

Subcortical extrapyramidal motor system – which drives spontaneous facial expressions of felt emotions

Cortical pyramidal motor system – which controls voluntary (faked) facial expressions.

While humans are unable to consistently spot the subtle differences between the two, the team says a computer can.

“The computer system managed to detect distinctive dynamic features of facial expressions that people missed,” says Marian Bartlett, lead author from UCSD. “Human observers just aren’t very good at telling real from faked expressions of pain.”