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Use blue light to immediately boost alertness

Teresa Tanoos's picture
Study says blue light instantly improves alertness during day and night.

If you’re feeling tired, but still have work to do, getting some exposure from short wavelength or blue light may give you the immediate boost you need, according to a study from Brigham and Women's Hospital (BWH).

Researchers at BWH found that direct exposure to blue light during the daytime instantly increased alertness and performance.

Prior research has shown that blue light improves alertness at night, but this is the first study to confirm it does the same during the day.

Lead author Shadab Rahman, PhD, a researcher in BWH’s Division of Sleep Medicine, says that the results of this new study, published in the February issue of Sleep, confirms the “alerting effect” of exposure to blue light during the day.

Using specialized lighting equipment, 16 participants in the study were exposed for 6.5 hours a day to equal amounts of either blue or green light to compare what kind of effect each color had on alertness and performance.

The participants were then asked to rate their level of sleepiness, while wearing electrodes that measured reaction times and any changes in brain activity during exposure to the light.

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As a result, the research team discovered that the participants who were exposed to blue light consistently rated themselves as more alert, and they had faster reaction times with fewer distractions during the performance tests, compared with the participants exposed to green light.

The blue light participants also had changes in brain activity that revealed a heightened state of alertness.

Steven Lockley, PhD, neuroscientist at BWH and senior investigator of the study, said that these findings contribute to a better understanding of the impact light has on the brain, opening up “a new range of possibilities” for how light can be used to increase alertness in humans.

For shift workers, particularly those who work overnight, Lockley says that using light to increase alertness also has “obvious safety benefits”. He added that such lighting also helps day shift workers see better and also heighten alertness while increasing productivity on the job.

How to incorporate better lighting in work places remains a challenge however. Although natural daylight is ideal, the researchers pointed out that it’s not always available in buildings where people work, live or attend school.

Nevertheless, there have been technological advancements that can improve access to natural daylight, including new lighting technologies that may bring the development of “smart” lighting systems that increase the availability of lighting that boosts alertness, productivity and safety.

SOURCE: Journal Sleep, Diurnal Spectral Sensitivity of the Acute Alerting Effects of Light, February 2014 issue