Mood-lifting bright light improves...reaction time?

It's often the case that a device or substance with a known benefit also comes with known risks--typically referred to as side effects and listed quickly at the ends of commercials. So it seems worth noting when a product's side effect may in fact be useful.

The Valkee, a portable headset launched in August of 2010, directs 8- to 12-minute doses of bright light through the ear canal and into the brain to improve seasonal affective disorder. It turns out that this concentration of bright light into the brain may also improve motoric reaction time, according to a study conducted by Verve Research in Finland.

The placebo-controlled study (meaning some were given the treatment and others a placebo in its place) tested the effects of the Valkee headset on Finnish national league ice hockey players and found that those exposed to 12 minutes of light via the headset sped up their already fast reaction times by 20 percent.

"The placebo-controlled study showed a significant improvement in motoric reaction times of top athletes using bright light via the ear canal," says lead researcher Mikko Tulppo in a news release.

All of which could be very exciting in the sports world, not to mention situations where faster reaction times improve safety--i.e. behind the wheel. But these results also beg the question: Does light exposure directly affect our reaction times, or is this merely correlative? And if it does, do the darker, winter months actually slow our reaction time? What about dark nights? How frequently would light therapy need to be administered to counteract darkness? Could light therapy improve the reaction times of long-distance truckers and pilots? Et cetera.

Clearly more research is required as scientists explore this relationship, but for those already using bright light to improve mood, consider faster reaction times an added bonus.