Abstract
Many physiological processes are rhythmic and differ between people as, for example, the times when we sleep or our daily levels of alertness. An internal biological clock regulates these rhythms and the natural alternation of day and night is essential for ensuring that our body clock is synchronised to the 24-h day. The relationship between external (social) and internal (biological) time is called phase of entrainment. Humans differing in this trait are different chronotypes (e.g. ‘early larks’ or ‘late owls’). However, as most of us spend too much time inside dimly-lit buildings, we do not receive sufficient light to stably synchronise our body clock. Hence, 80% of the general working population rely on alarm clocks to awaken on workdays, because of their late ‘ticking' body clocks. By definition these people are chronically sleep deprived. From controlled laboratory studies, there is clear evidence showing the detrimental effects of sleep deprivation on health and performance, with consequences that would be catastrophic in real life – especially in shift-work occupations. This problem is pronounced in especially late chronotypes (people with a late phase of entrainment), showing an increased risk of a phenomenon that has been coined social jetlag - which, in turn, is positively associated with increased smoking, obesity, depression, cardiovascular risk and decreased academic performance. In a nutshell, by shielding ourselves too much from natural light and through widespread and uncontrolled use of artificial light, we create un-natural light/dark cycles that interfere with the entrainment of our biological clock. The consequences cover chronic sleep loss, circadian misalignment and adverse lifestyle habits, which all potentially threaten our health. In my lecture, I will present an overview of my current and past research that aims to better understand the biology and psychology of well-timed work, leisure and health.
3 selected papers:
a) Kantermann, Juda, Merrow, Roenneberg (2007). The human circadian clock’s seasonal adjustment is disrupted by daylight saving time. Curr. Biol. 17:1996-2000. b) Kantermann, Wehrens, Ulhoa, Moreno, Skene (2012). Noisy and individual, but doable: shift-work research in humans. Prog. Brain. Res. 199:399-411. c) van der Vinne, Zerbini, Siersema, Pieper, Merrow, Hut, Roenneberg, Kantermann (2015) Timing of exams affects school performance differently in early and late chronotypes, J. Biol. Rhythms 30(1):53–60.
CV
Dr. Kantermann studied Biology and Psychology at the University of Bielefeld. After obtaining his PhD from the Ludwig-Maximilians-University Munich, he has taken on various academic positions at University of Rostock (Institute for Anatomy and Neuroembryology), LMU Munich (Centre for Chronobiology), University of Surrey (Chronobiology) and Charité Berlin (Centre for Interdisciplinary Sleep Medicine). Currently he is researcher in the Groningen Institute for Evolutionary Life Sciences, University of Groningen.
CBBM Lecture "The biology and psychology of timed work, leisure and health"
