Zoning in

Researchers at Brigham and Women's Hospital and the University of Michigan have developed a software program that prescribes a regimen for avoiding jet lag.

Travelling across several time zones can cause an individual to experience jet lag, which includes trouble sleeping at night and difficulty remaining awake during the day. These effects are caused by a lack of synchronisation between the body's internal time clock and local environmental cues.

The researchers' program, which seeks to re-synchronise the body with its new environment, considers inputs such as background light level and the number of time zones travelled.

Then, based on a mathematical model, it gives users exact times of the day when they should apply countermeasures such as bright light to intervene and reduce the effects of the jet lag.

Timed light exposure is a well-known synchronisation method, and when used properly, can reset an individual's internal clock to align with local time. The result is more efficient sleep, a decrease in fatigue, and an increase in cognitive performance.

Although the method is not available to the public, it has direct implications for designing schedules for jet lag, shift work, and extreme environments, such as in space, undersea or in polar regions.

'The work shows how interventions can cut the number of days needed to adjust to a new time zone by half,' said researcher Daniel Forger.

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.