Sleep, physical, and mental wellbeing in a modern society – relevance of stress, media consumption, and artificial light
Freitag, 04.06.2021:
14:45 - 16:15

Chair der Sitzung: Christine Blume, Universität Basel
Chair der Sitzung: Christian Benedict, Uppsala University
Ort: Learning, memory, and sleep

Zusammenfassung der Sitzung

Sleep is critical for physical health and mental well-being and sleep disturbances have been associated with a range of adverse health effects. At the same time, sleep disturbances are very common in modern societies. In Germany, about 30% of the population reported clinically relevant sleep problems in the past four weeks in a representative survey conducted between 2008 and 2011. The overall increase in numbers over the past 20-30 years suggests that several factors related to modern lifestyle may negatively affect sleep. In this symposium, we would like to revisit different aspects of such a modern lifestyle and discuss their relationship to sleep, physical health, and mental wellbeing. Specifically, Johanna Schwarz’s presentation will focus on the effect of sleep deprivation on the response to psychosocial stress. Next, Sandrine Baselgia will show how arousing effects of cliff-hangers and binge-watching of Netflix series modulate sleep. Christine Blume will present findings on how artificial light exposure before sleep affects neuroendocrinology, sleep quality, and basic human brain functions. The symposium will be concluded by Christian Benedict, who will present research on how acute sleep loss affects weight control as an important health factor. Altogether, this symposium highlights the effects of several characteristics of a modern lifestyle on sleep and investigates their relevance for mental and physical health. The symposium will be concluded with a broader discussion on how the research findings might translate into societal efforts to promote better sleep.


Binge-watching in the sleep laboratory - effects of cliffhangers on sleep

Sandrine Baselgia, Selina L. Combertaldi, Dominique Wirz, Alexander Ort, Andreas Fahr, Björn Rasch

University of Fribourg, Switzerland

Binge-Watching -the consumption of multiple episodes of a series in a rapid succession- is a widespread phenomenon, especially among young adults. To engage viewers into continuous watching, series consist of interesting characters and story lines with open ending that abruptly end during critical scenes ("cliffhangers"). Such unfinished narratives are believed to create arousal and cognitive engagement beyond the viewing activity. Empirical studies indicate that binge-watching can impair subjective measures of sleep, mediated by pre-sleep arousal. However, the effects of binge-watching and cliffhangers on objective sleep parameters are still unknown.

56 healthy young participants either watched 3-4 episodes of a suspensful series or a neutral control series before sleep in the sleep laboratory, in a within-subject design. In one group of participants, the suspensful series ended with a cliffhanger; in the other group, the same series ended before the cliffhanger. As expected, binge-watching session with cliffhangers did result in higher cognitive and physiological pre-sleep arousal as compared to series without cliffhangers and control series. In contrast to our expectation, neither subjective nor objective sleep parameters were impaired. Objective sleep onset latency was even significantly shorter in the series condition compared to control. Fine-grained power analysis revealed increased alpha power during rapid-eye-movement (REM) sleep and lower power in the slow oscillations band during Non-REM sleep in the cliffhanger condition.

Our results speak against large impairments of binge-watching and cliffhangers on sleep quality and architecture. However, unfinished narratives might induce more subtle changes in oscillatory power during sleep, possibly reflecting ongoing cognitive processing.

Bad sleep makes it harder to keep your waistline down

Christian Benedict

Uppsala University, Schweden

Do you know this feeling when you had an insufficient night of sleep, and the first thought is where the cookies and chocolate are? According to epidemiological research, there is a strong association between short sleep duration and the risk of being either overweight or obese. As we all know, correlation does not imply causation. Thus, together with colleagues from Germany and Sweden, I performed a series of human experiments in metabolically healthy young adults to investigate whether acute sleep loss alters central nervous and peripheral pathways involved in body weight regulation in favor of weight gain. Some of these results will be presented in my talk.

Pre-sleep artificial light exposure does not alter basic cognitive processing during sleep

Christine Blume1,2, Christian Cajochen1,2

1Centre for Chronobiology, Psychiatric Hospital of the University of Basel, Switzerland; 2Transfaculty Research Platform Molecular and Cognitive Neurosciences, University of Basel, Switzerland

Introduction: Short (“blue”) wavelength artificial light is known to increase alertness in the evening and negatively affect sleep. Whether the alertness-promoting effects also alter basic sensory processing is however unknown. Here, we investigated the acute (wake) and delayed (sleep) effects of pre-sleep light exposure (LE) on the brain’s ability to generate top-down predictions about forthcoming events and compare them to bottom-up sensory input. We specifically hypothesised that short-wavelength enriched LE would increase alertness and thereby render sensory processing during sleep more “wake-like”.

Methods: Twenty-nine healthy participants (23.2±2.8 years) were exposed to two metameric light sources for one hour starting 1h50min prior to an 8-h sleep episode. Light sources differed only in their effect on melanopsin-expressing retinal ganglion cells (mel-high vs. mel-low, contrast 208%). During LE and the ensuing night, volunteers underwent a hierarchical auditory stimulation paradigm. Sensory processing was evaluated on the basis of event-related potentials (ERPs) and time-frequency responses (TFRs, 1-15Hz) using cluster-based permutation statistics.

Results: As hypothesised, high-melanopic LE suppressed melatonin secretion more effectively than low-melanopic LE. However, we found no evidence of a differential modulation of the relationship between top-down predictions and (omitted) bottom-up sensory input during wakefulness or any sleep stage. Likewise, neither subjective sleepiness and behavioural alertness during wakefulness nor sleep parameters differed between the LE conditions.

Conclusions: The results suggest that sensory processing during wakefulness and sleep is not differentially altered by 1-h exposure to a high- (vs. low-) melanopic light source. Basic cognitive processing thus does not seem to become more “wake-like”.

The effect of sleep deprivation on the response to acute psychosocial stress in young and older adults

Johanna Schwarz1, Andreas Gerhardsson1,2, Wessel van Leeuwen1, Mats Lekander1, Mats Ericson3, Håkan Fischer2, Göran Kecklund1, Torbjörn Åkerstedt1

1Stress Research Institute, Department of Psychology, Stockholm University, Sweden; 2Department of Psychology, Stockholm University, Sweden; 3Division of Ergonomics, CBH-School, Royal Institute of Technology, Sweden


Sleep loss and psychosocial stress have negative consequences for well-being, health and performance ability. Despite the intuition that sleep and stress are linked in both directions, little research has focused on the effect of sleep deprivation on the response to acute psychosocial stress.


In this study 124 young (18–30 years) and 94 older (60–72 years) healthy adults participated in one of the following conditions: i. normal night sleep & Placebo-Trier Social Stress Test (TSST), ii. normal night sleep & TSST, iii. sleep deprivation & Placebo-TSST, iv. sleep deprivation & TSST. Subjective stress ratings, salivary cortisol, heart rate variability (HRV) and salivary alpha amylase (sAA) were repeatedly measured as indicators of the stress response.


Already at the pre-TSST baseline measurement, sleep deprived participants rated their stress levels higher and had higher cortisol values than rested participants. However, sleep deprivation did not significantly change the reactivity to and recovery from the TSST for any of the outcome measures. Age did not moderate the effect of sleep deprivation. In older adults, subjective stress ratings and sAA levels were higher, and HRV lower at baseline. Cortisol trajectories and HRV differed across the test session between the two age groups.


The results suggest that while self-reported stress and cortisol levels are increased after sleep deprivation, the response to an acute psychosocial challenge is not markedly changed after one night without sleep.

The study was funded by Riksbankens Jubileumsfond.