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"Using Math to Take the Lag Out of Jet Lag"

June 19, 2009

Brigham and Women's Hospital Press Release: Researchers develop computational method for aligning internal body clock with local, environmental time.

BOSTON, MA. - Traveling across several times zones can cause an individual to experience jet lag, which includes trouble sleeping at night and trouble remaining awake during the day. A major cause of these effects is the desynchronization between the body's internal time clock with local environmental cues. Researchers at Brigham and Women’s Hospital (BWH) and the University of Michigan (U-M) have developed a mathematical, computational method for determining optimal light stimuli to re-synchronize the body’s clock to the local environmental time.  These findings are published in the June 19, 2009 issue of PLoS Computational Biology.

Timed light exposure is a well known method for synchronizing an individual's internal clock with the environment and when used properly, this intervention can reset an individual's internal clock to align with local time resulting in more efficient sleep, a decrease in fatigue, and an increase in cognitive performance. Poorly timed light exposure can prolong the re-synchronization process.

“Because the timing of proper light exposure is so important in synching the internal clock with local time, we have developed this mathematical computation to automate the process of determining the timing of appropriate light cues,” said Dennis Dean, a researcher in the Division of Sleep Medicine at BWH and the paper’s lead author.

The next phase of this research includes the addition of interventions such as naps, caffeine and melatonin to help the process of realigning the internal body clock while reducing decreased performance experienced during travel across time zones.

To learn more about why sleep matters, the science behind it and how to improve your sleep, visit

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