Just Your Imagination…Or Is It?

by Melanie Moran 1,470 views No Comment Print  E-mail

Letting your imagination run away with you may actually influence how you see the world.

Tong and Pearson

New research published in the online journal Current Biology has found that mental imagery—what we see with the “mind’s eye”—directly affects our visual perception.

“We found that imagery leads to a short-term memory trace that can bias future perception,” says Joel Pearson, research associate in the Vanderbilt Department of Psychology and lead author of the study. “This is the first research to definitively show that imagining something changes vision both while you are imagining it and later on.”

To test how imagery affects perception, the researchers had subjects imagine simple patterns of vertical or horizontal stripes. They then presented a green horizontal pattern to one eye and a red vertical pattern to the other to induce what is called binocular rivalry. During binocular rivalry an individual will often alternately perceive each stimulus, with the images appearing to switch back and forth before their eyes. The subjects generally reported they had seen the image they had been imagining, proving the researchers’ hypothesis that imagery would influence the binocular rivalry battle. 

Frank Tong, associate professor of psychology and co-author of the study, says “Our results show that even a single instance of imagery can tilt how you see the world one way or another, dramatically, if the conditions are right.”

The new findings offer an objective tool to assess the often-slippery concept of imagination. “We found that the imagery effect, while found in all of our subjects, could differ a lot in strength across subjects. So this might give us a metric to measure the strength of mental imagery in individuals and how that imagery may influence perception,” Tong says.

The findings by Pearson, Tong and co-author Colin Clifford of the University of Sydney may also help settle a longstanding debate in the research community over whether mental imagery is visual—that one imagines something just as one sees it—or more abstract.

“With advances in human brain imaging, we now know that when you imagine something, parts of the visual brain do light up and you see activity there,” Pearson says. “Our work shows that not only are imagery and vision related, but imagery directly influences what we see.”

photo credit: Steve Green