Fear Can Alter Depth Perception
October 23, 2012 by Sam Rolley
Preppers and survival experts often note how the body’s reaction to fear affects different senses vital to survival. According to a new study, fear can make you underestimate the distance between you and a potential threat.
“Our results show that emotion and perception are not fully dissociable in the mind,” said psychologist Stella Lourenco, co-author of the study published in Current Biology. “Fear can alter even basic aspects of how we perceive the world around us. This has clear implications for understanding clinical phobias.”
In general, people have a good sense for when objects heading toward them will make contact, giving them a split second to react by ducking or bracing for the object to strike them. The researchers sought to test the effect of fear on the accuracy of that skill.
The researchers had study participants make time-to-collision judgments of images on a computer screen. The study participants were instructed to gauge when each of the images, which varied from pictures of butterflies and rabbits to ones of menacing snakes and spiders, on the computer screen would have collided with them by pressing a button. The researchers found that the study participants often thought the snakes and spiders were closer than the less threatening visuals.
“We’re showing that what the object is affects how we perceive looming. If we’re afraid of something, we perceive it as making contact sooner,” said Matthew Longo, a psychologist at Birkbeck, University of London.
“Even more striking,” Lourenco added, “it is possible to predict how much a participant will underestimate the collision time of an object by assessing the amount of fear they have for that object. The more fearful someone reported feeling of spiders, for example, the more they underestimated time-to-collision for a looming spider. That makes adaptive sense: If an object is dangerous, it’s better to swerve a half-second too soon than a half-second too late.”