Eyes reveal what we want to conceal: Study
WASHINGTON, Aug 22: Tracking eye movement can reveal when a person recognizes another, even when they try to hide it, according to new research.
Attempts to conceal recognition made it easier to spot in the new study, which could be used in criminal investigations to gain information from uncooperative witnesses or suspects.
Lie-detector tests are used in such cases as criminal investigations and U.S. Federal Bureau of Investigation interviews, but the results are notoriously unreliable. When asked questions critical to a criminal case, a racing heartbeat or sweaty palms might incriminate a nervous truth-teller, while a practiced liar may be able to control those signs and avoid suspicion.
A team led by Ailsa Millen, a psychology researcher at Britain's University of Stirling, tested a different method to extract information: tracking the movement of people's eyes as they look at photographs of faces. Instead of detecting the physical response to lying, which can be misleading, the researchers looked for the hidden information itself: the knowledge of a familiar face.
"Humans are experts at familiar face recognition. Recognition of a familiar face is fast and reflexive," said Millen.
Your eyes trace a familiar face differently than they do an unfamiliar one. When people look at unfamiliar faces, their eyes tend to dance from feature to feature, pausing frequently but briefly as they try to identify the unknown person. When gazing at familiar faces, people tend to linger on just a few features.
The researchers wanted to know if people could control their eye movements when attempting to hide the fact that they recognized a familiar face - or if their eyes would give them away.
They showed 48 students pictures of strangers and familiar professors. They asked participants to try to appear honest while lying about recognizing familiar faces.
The researchers gave half the participants a method they thought might help them hide their recognition: pausing in the same places as they looked at each face, starting from the forehead, then stopping at each eye as they move from one ear to the other, then down to the nose, mouth and chin. -VOA