Sound and vision work hand in hand, UCLA psychologists report

UCLA:

Our senses of sight and hearing work closely together, perhaps more than people realize, a new UCLA psychology study shows.

“If we think of the perceptual system as a democracy where each sense is like a person casting a vote and all votes are counted to reach a decision — although not all votes are counted equally — what our study shows is that the voters talk to one another and influence one another even before each casts a vote,” said Ladan Shams, a UCLA associate professor of psychology and the senior author of the new study.

In the study of how one sense can affect another, Shams, an expert on perception and cognitive neuroscience, and her colleagues showed 63 participants a large number of dots on a screen in two separate phases, with a break between the phases. In one phase, the dots moved around randomly; in the other, some of the dots moved together from right to left. In both phases, the dots were accompanied by sound.

Over a series of experiments, the researchers asked the participants to correctly identify the phase in which the dots moved together horizontally.

Participants were divided into three groups. One group heard sound moving from right to left as the dots moved from right to left, and they heard sound that remained stationary during the random phase. A second group heard the right-to-left sound during both phases. And a third group heard sound moving in the opposite direction — from left to right — during both phases. Then, each participant experienced trials in all three conditions.

Read the whole story: UCLA