Is seeing believing? People are not good at identifying where sights, sounds originate

http://www.eurekalert.org/pub_releases/2015-12/uoc--isb120815.php

Public Release: 8-Dec-2015
Is seeing believing? People are not good at identifying where sights, sounds originate
Study by UCLA psychologists reveals that our senses are far from flawless
University of California - Los Angeles

Our vision and hearing aren't as reliable as we might think, according to a study by life scientists at UCLA.

"Our basic sensory representation of the world -- how information from our eyes and ears is processed by neurons in the brain -- is inaccurate," said Ladan Shams, an associate professor of psychology in the UCLA College and senior author of the research, which was published today in the journal PLOS Computational Biology.

"We tend to view our senses as flawless and think that to see is to believe," she said. "So it's eye-opening to learn that our perceptions are flawed."

•••••

The scientists played brief bursts of sound and triggered flashes of light, in various combinations, and asked participants to identify where they originated. A total of 384 people, most between the ages of 18 and 22, participated; they typically were asked to identify about 525 stimuli during a 45-minute test.

In general, they fared poorly when the light and sound were played alone. Participants mostly believed that the light sources were closer to the center of the screen than they actually were, and that noises were coming from closer to the periphery.

"The auditory task was especially difficult," said Brian Odegaard, a UCLA postdoctoral scholar who was the study's lead author.

•••••

"Maybe evolution has favored high precision in the center of the visual field," she said. "We are really good at localizing and discriminating at high acuity in the center of our vision, and that comes with the cost of making more errors at outer areas."

The study participants did, however, answer much more accurately when the flashes and noise were played simultaneously at the same location.

"The brain is wired to use information from multiple senses to correct other senses," Shams said. "The saying is true: 'If you want to hear better, put your glasses on.'"

•••••