Phase shifting two coupled circadian pacemakers: implications for jet lag.
Level 5 - mechanism / opinion, no new human data
Mathematical modeling and simulation study with illustrative comparison to four case studies.
PubMed 4073291 · doi:10.1152/ajpregu.1985.249.6.R704
What was done
A coupled two-oscillator computational model was applied to simulate the human circadian system's response to transmeridian time zone shifts. The model's behavior was analyzed under varying conditions, including direction of travel (eastward versus westward), number of time zones crossed, zeitgeber strength, and variations in intrinsic pacemaker period parameters. Model simulations were compared against empirical sleep-wake and core body temperature recordings from four human subjects undergoing transmeridian flights.
What was found
The abstract reports no specific numerical values or statistical effect sizes. The model demonstrated that resynchronization rate depends on the rhythm measured, flight direction (eastward vs. westward), number of time zones crossed, and zeitgeber strength in the new time zone. Variation in intrinsic pacemaker period parameters accounted for intersubject variability, and individualized period estimates enabled simulation of sleep-wake and core temperature patterns in four subjects.
Why it matters
The paper demonstrates that key features of jet lag and individual differences in recovery can be explained by fundamental properties of coupled circadian oscillators.
Limits
The abstract provides no quantitative metrics or fit statistics. Empirical validation was limited to four case studies, and the theoretical model simplifies complex human neurobiology.
Cited by
- supports The circadian literature indicates that it takes about an hour per day to adjust to time zone shifts, adjusting faster when traveling west than east.