Fear can skew our spatial perception of approaching objects, suggests a study published in Current Biology.
Stella Lourenco, from Emory University and Matthew Longo at Birkbeck tested the effect of fear on the accuracy of estimating when objects heading towards the subject would make contact with them.
“Our results show that emotion and perception are not fully dissociable in the mind. Fear can alter even basic aspects of how we perceive the world around us. This has clear implications for understanding clinical phobias,” said Lourenco.
Humans generally have a well-developed perception for when objects heading towards them will make contact. Study participants made time-to-collision judgements of images on a computer screen. The size of the images increased over one second before disappearing, to simulate “looming,” an optical pattern used instinctively to judge collision time.
The participants tended to overestimate the distance away from images of threatening objects such as spiders or snakes, compared to non-threatening images such as butterflies or rabbits.
The traditional view of looming is as a purely optical cue to object approach, but this study challenges this.
“We’re showing that what the object is affects how we perceive looming. If we are afraid of something, we perceive it as making contact sooner,” said Longo
The researchers also suggest that it is possible to predict how much a participant will underestimate an object’s collision time by assessing how much that object scares them.
“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,” added Lourenco.
However, the researchers note that it is unclear whether fear of an object makes it appear to travel faster, or whether that fear makes the participant expand their sense of personal space (generally about an arm’s length away)
“We’d like to distinguish between these possibilities in future research,” Lourenco stated.