Simulation of the Ontogeny of Social Jet Lag: A Shift in Just One of the Parameters of a Model of Sleep-Wake Regulating Process Accounts for the Delay of Sleep Phase Across Adolescence.

Arcady A Putilov,Evgeniy G Verevkin

doi:10.3389/fphys.2018.01529

Abstract

The term “social jet lag” was introduced for defining the conflict between social and biological clocks due to the general practice of shifting weekday risetime on early morning hours. The phase delay of the sleep-wake cycle during adolescence is one of the most remarkable features of the ontogenesis of sleep that is incompatible with early school start times. It was previously proposed that the process of accumulation of sleep pressure during wakefulness is slowing down in post-pubertal teens to allow them to stay awake for a longer period of time thus causing the delay of their bedtime. In order to examine this proposition, we traced the ontogeny of social jet lag using sleep times reported for 160 samples of study participants of different ages as an input to a model of sleep-wake regulatory process. The simulations suggested that a gradual change in just one of the model’s parameters, the time constant of wakefulness phase of the sleep-wake regulatory process, might explain the association of the transition between childhood and adulthood with the prolongation of time staying awake, delay of sleep time, and reduction of sleep duration. We concluded that the implication of the sleep-wake regulating model would be of help for understanding precisely how social jet lag varies with age and what are the chronophysiological causes of this variation.

Highlights

We argued that the implication of this model of sleep-wake regulation would provide understanding of how social jet lag varies with age and what are the chronophysiological underpinnings of this variation
In our simulations (Figures 1–3), bedtimes and risetimes were predicted as the switches between buildup and decay phases of the sleep-wake regulatory process that was disturbed on weekdays by social clocks
The most prominent of these changes is the dramatic sleep phase delay in the course of adolescence that was proposed to be linked to the increase in time constant of the buildup phase of the sleep-wake regulating process

Summary

Introduction

Epidemic of sleep deprivation among adolescents when schedules maintained during the school year are resulted in insufficient and ill-timed sleep was recognized in many post-industrial societies with different cultural traditions (Spruyt et al, 2005; Chung and Cheung, 2008; Liu et al, 2008; Carskadon, 2011; Kim et al, 2011; Perkinson-Gloor et al, 2013; Short et al, 2013; Borisenkov et al, 2016; Carissimi et al, 2016; Komada et al, 2016; Gariépy et al, 2017). Wittmann et al (2006) introduced the term “social jet lag” to conceptualize the conflict between social and biological clocks and to propose a methodology for assessment of its severity (originally by means of a questionnaire) The results of such assessments supported the concern about exaggeration of social jet lag due to a confrontation between early school times and adolescents’ biological tendency to delay (see, e.g., Crowley et al, 2014). It is not clearly understood why adolescents are often more susceptible to social jet lag than either young adults or children, even after accounting for differences between ages in sleep duration

Methods

Results

Conclusion