Mental HealthUsing Math To Take The Lag Out Of Jet Lag
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 using timed light exposure. The method is described in an article
published June 19 in the open-access journal PLoS Computational Biology.
Traveling across several times zones can cause an individual to experience
jet lag, which includes trouble sleeping at night and difficulty remaining
awake during the day. These effects largely reflect de-synchronization
between the body"s internal time clock and local environmental cues.
The program, which seeks to re-synchronize the body with its new
environment, considers inputs like background light level and the number
of time
zones traveled. Then, based on a mathematical model, the program gives
users exact times of the day when they should apply countermeasures such
as
bright light to intervene and reduce the effects of jet lag.
Timed light exposure is a well known synchronization method, and when used
properly, this intervention 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. Poorly timed light
exposure can prolong the re-synchronization process.
Using their computational method, researchers simulated shifting
sleep-wake schedules and the subsequent light interventions for realigning
internal
clocks with local time. They found that the mathematical computation
resulted in quicker design of schedules and also predictions of
substantial
performance improvements. They were able to show that the computation
provided the optimal result for timing light exposure to reduce jet lag
symptoms.
"Using this computation in a prototyped software application allows a user
to set a background light level and the number of time zones traveled to
obtain a recommendation of when to expose a subject to bright light, such
as the bright lights sometimes used to treat Seasonal Affective Disorder"
said lead-author Dennis Dean. "Although this method is not yet 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."
"This work shows how interventions can cut the number of days needed to
adjust to a new time zone by half," said co-author 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 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 http://healthysleep.med.harvard.edu
Citation:
"Taking the Lag out of Jet Lag through Model-Based Schedule Design."
Dean DA II, Forger DB, Klerman EB (2009)
PLoS Comput Biol 5(6): e1000418 doi:10.1371/journal.pcbi.1000418
PLoS Computational Biology