The researchers videotaped the participants and their reactions, compiled images of about 700 emotional expressions, and assigned "coders" to examine about 100,000 frames.
"While our research did detect several microexpressions, leakage of unintended emotions typically lasted longer," ten Brinke said. "We found that when a lying participant's face revealed unintended emotions, it typically lasted for closer to a second but usually only occurred in either the upper or lower face."
Dr. Daniel Langleben, an assistant professor of psychiatry at the University of Pennsylvania, said brief and revealing but unconscious facial expressions do appear to be a real phenomenon, although it's difficult for people to detect them. Computers, he said, may do a better job.
"A computer that looks [at a face] using facial-recognition software doesn't care if it's red, black, white or green or whether it reminds you of your grandmother or if the face is ugly or pretty," he said.
Ten Brinke said the next step is to create research that better reflects real life by studying emotional deceptions that could have serious consequences.
The Canadian researchers have collected about 60 videotaped appeals from family members pleading to the public for the return of their missing relatives. In about half of the cases, the people in the videotapes actually killed the relatives, she said.
"We will be examining the faces of these individuals for cues to deceit in this real-life context," ten Brinke said.
Learn more about facial expressions from Carnegie Mellon University.
SOURCES: Leanne ten Brinke, B.Sc., graduate student, Dalhousie University, Halifax, Nova Scotia, Canada; Daniel Lang
All rights reserved