People who have difficulty seeing traffic lights or cars at night,  facial gestures, or when a flame is burning on a stove often suffer from poor contrast sensitivity, a condition thought to be correctable, if at all, only by eyeglasses, contact lenses or surgery. Researchers now say they may have found a way to improve contrast sensitivity naturally with the help of an unlikely source—video games.

In a study published today online in the journal Nature Neuroscience a team of researchers led by University of Rochester in New York State professor of brain and cognitive sciences Daphne Bavelier describe a specific video game training regimen that could improve contrast sensitivity, helping those afflicted with the problem notice even very small changes in shades of grey against a uniform background. Poor contrast sensitivity affects thousands of people worldwide, including the elderly and those suffering from amblyopia, also known as "lazy eye," Bavelier says.

Over the past several years researchers at the Rochester and Goldschleger Eye Research Institute in Israel have studied the ability of certain types of video games to improve different aspects brain function and visual processing, tipped off to this possibility by the observation that avid action-oriented games players can quickly home in on targets amidst chaotic visual scenes. Research published in 2007 in the journal Psychological Science and 2003 in Nature indicated that action-filled video games significantly sharpen vision, helping the brain focus on visually complex situations, keep track of multiple items at once and process fast-changing information.

Bavelier and her colleagues discovered that expert video game players who favor games filled with action (viewed from the first-person point of view) have better contrast sensitivity than those who play games involving puzzles or some other less intense activity. To determine whether action-packed video games, as opposed to some other factor, were the reason for the enhanced contrast sensitivity the researchers chose subjects without a lot of experience playing shooter, sports or driving simulation video games and had them develop their skills over 50 hours of play (spanning eight to 10 weeks). Those who played the action-packed video games such as Unreal Tournament 2004 by Atari and Call of Duty 2 by Infinity Ward experienced an improvement in contrast sensitivity, while those playing The Sims 2 by Electronic Arts did not.

The latest research stands out from the previous experiments because contrast sensitivity is something that people thought could not be changed naturally, Bavelier says, adding, "What we showed is that you can train your brain to make better use of the information it receives from the retina." Games that best improved contrast sensitivity were those that were unpredictable and required the player to aim at different targets, quickly deciding friend from foe before firing their weapon. "You always need to be alert and analyze what's going on," she adds.

A crucial component of the research was ensuring that the study participants experienced permanent improvement in their contrast sensitivity. The researchers first tested the subjects two days after their training ended and checked back with them sometime between six months and two years later (they were asked not to play video games during that time). "We didn't want to test the arousal they felt directly after playing the video game," Bavelier says.

Bavelier and her colleagues now want to apply what they have learned about improving contrast sensitivity to help those suffering from amblyopia, helping to give them stereo vision, where both eyes work together. The researchers will also study people whose contrast sensitivity has deteriorated due to aging to see if their video game therapy can help augment their vision and perception.

Another area of interest is figuring out exactly what it is about certain video games that improve learning, with the hope of someday creating a tool kit that video game developers can use to make their work more beneficial to memory enhancement, perception and other mental capabilities. Bavelier has worked to keep her research from endorsing any particular video game, or even video game play itself. Still, she says, "it's pretty amazing that [game developers] have intuitively recreated a lot of factors for learning."

Image © Cristian Ardelean