Mostly Biomathematics Lunchtime Seminar

Reentrainment of the circadian pacemaker during jet lag: east-west asymmetry and the effects of north-south travel

Speaker: Amitabha Bose, Department of Mathematical Sciences, New Jersey Institute of Technology

Location: Warren Weaver Hall 1314

Date: Tuesday, October 17, 2017, 12:30 p.m.


The normal alignment of circadian rhythms with the 24-hour light-dark cycle is disrupted after rapid travel between home and destination time zones, leading to sleep problems, indigestion, and other symptoms collectively known as jet lag. Using mathematical and computational analysis, we study the process of reentrainment to the light-dark cycle of the destination time zone in a model of the human circadian pacemaker. Techniques from dynamical systems are used to reduce the study to focus on the dynamics of one-dimensional, discontinuous maps. We then calculate the reentrainment time for travel between any two points on the globe during any season and explain several properties of jet lag, such as why most people experience worse jet lag after traveling east than west. Contrary to the conventional wisdom that jet lag only occurs after east-west travel across multiple time zones, we show that the change in daylength encountered during north-south travel across the equator can cause jet lag even when no time zones are crossed.