Multimodal in-vehicle lighting system increases daytime light exposure and alertness in truck drivers under Arctic winter conditions.

Drowsiness while driving negatively impacts road safety, especially in truck drivers. The present study investigated the feasibility and alerting effects of a daylight-supplementing in-truck lighting system (DS) providing short-wavelength enriched light before, during, and after driving. In a within-participants design, eight truck drivers drove a fully-loaded truck under wintry Scandinavian conditions (low daylight levels) with a DS or placebo system for five days. Subjective and objective measures of alertness were recorded several times daily, and evening melatonin levels were recorded three times per study condition. DS significantly increased daytime light exposure without causing negative side effects while driving. In addition, no negative carry-over effects were observed on evening melatonin and sleepiness levels or on nighttime sleep quality. Moreover, objective alertness (i.e., psychomotor vigilance) before and after driving was significantly improved by bright light exposure. This effect was accompanied by improved subjective alertness in the morning. This field study demonstrated that DS was able to increase daytime light exposure in low-daylight conditions and to improve alertness in truck drivers before and after driving (e.g., during driving rest periods). Further studies are warranted to investigate the effects of daylight-supplementing in-cabin lighting on driving performance and road safety measures.

Preventive Effect of a 7-Week App-Based Passive Psychoeducational Stress Management Program on Students.

Passive psychoeducation is an easily accessible and cost-effective self-guided intervention that does not use elements of active psychotherapies or require homework. The present study aimed to investigate the acceptability and efficacy of a 7-week app-based passive psychoeducation stress management program to promote adaptive emotion regulation and coping skills in university students (i.e., 80% psychology students). Participants were tested via Lime-Survey® at pre- and post-test with the Depression Anxiety Stress Scale-21 (DASS-21), the Response Styles Questionnaire (RSQ), and the Emotion Regulation Questionnaire (ERQ). A stratified permutation block randomization by age, gender, and the DASS-21 stress subscale was performed. Each week, the psychoeducation group (n = 123) received different psychoeducation modules. At the end of each module, participants answered questions about their satisfaction with each module and adherence to psychoeducation. The control group (n = 130) received no intervention. The psychoeducation program led to a significant improvement in the adaptive emotion regulation strategy: "reappraisal" (p = 0.004) and a significant reduction in the dysfunctional coping style: "symptom-related rumination" (p = 0.01) but not to a significant reduction in depression, anxiety, and stress scores compared to the control group. Thus, the present study might demonstrate a preventive effect of an app-based passive psychoeducation program in students with low clinically relevant psychopathological symptoms.

Impact of repeated morning bright white light exposures on attention in a simulated office environment.

Attention is essential to the work. This study investigated the effects of two different light pulses on a simple attention task. In addition, the effects of subsequent exposure to constant but different illuminance levels on the continuation of the simple attention task and a subsequent complex attention task were examined. A total of 56 subjects were assigned in random order to two white light interventions that were repeated five times during the morning. Each light intervention consisted of a brief light pulse followed by constant light exposure and differed in temporal dimming dynamics and corneal illuminance. Subjective and psychometric parameters were recorded several times during light exposure. Heart rate variability (HRV) was derived from continuous electrocardiograms. Subjects showed improved reaction speed in the simple attention task, accompanied by higher HRV under a brighter light pulse without habituation by repetition. This difference in simple attention performance disappeared when light exposure remained the same after the light pulse. In addition, higher reaction speed and HRV were observed in the complex attention task under constant bright light exposure. Intermittent bright light seems promising to acutely improve attentional performance in office workplaces. Future research is needed to investigate daytime light effects on other work-related cognitive functions.

Effects of variable lighting intensities and colour temperatures on sulphatoxymelatonin and subjective mood in an experimental office workplace.

Workplace illumination is of paramount importance in determining the employee's productivity and well-being. Moreover, light exerts non-visual effects with respect to biological rhythms. In this study, we investigated the impact of different lighting conditions (500-1800 lx, 6500 K; 500 lx, 4000 K) on sulphatoxymelatonin (aMT6-s) and subjective mood in an experimental office accommodation. Urinary aMT6-s concentrations were significantly decreased at all days of the experiment in both lights. On day 3, differences between aMT6-s concentrations in specimen collected at 05:00 p.m. and at 09:00 a.m. were significantly higher under variable lighting conditions. Analyses of a mood rating inventory revealed a benefit of variable light with respect to the dimensions of "Activity", while "Deactivation" and "Fatigue" were increased in regular light on day 1. "Activity", "Concentration", and "Deactivation" changed in opposite directions when comparing variable with regular illumination on two consecutive days. In conclusion, variable light exerts a potential advantage in indoor office accommodations with respect to subjective mood, although no unequivocal differences in the profile of aMT6-s were found as compared to regular light.