Cycle-dependent oscillations in sex hormones affect sleep and cognition [59]. Moreover, Baker
Cycle-dependent oscillations in sex hormones have an effect on sleep and cognition [59]. On top of that, Baker and Drivers [60] reported hormonal cycle-dependent adjustments in sleep architecture in naturally cycling girls. While guys are less subject to monthly hormonal fluctuations, melatonin [61] and cortisol [62] secretion are also impacted by seasonal alterations in men. In addition to these problems of our study protocol and our sample, research examining light influences differ significantly relating to the applied show size and type (e.g., LED or LCD screens and computers, e-book readers or tablets/smartphones), brightness and size. Furthermore, Chellappa [3] concludes that circadian photosensitivity is topic to interindividual variations, i.e., the response to artificial light within the evening, for example adjustments of circadian parameters, varies largely across people. An example for anClocks Sleep 2021,individual trait responsible for the higher variance in light-susceptibility across individuals may be eye pigmentation, as a single study reported stronger melatonin suppression in subjects with lighter eye colors (i.e., blue, green or light-brown iris in comparison with dark brown iris) [63]. Hence, we can not rule out that we integrated more high- than low-responders or the other way about. Apart from Nimbolide Protocol common interindividual variations in sensitivity to light, it can be moreover impacted by age [28]. Younger adults showed much stronger lightinduced adjustments in circadian (i.e., endogenous melatonin secretion) and sleep parameters (i.e., frontal SWA), subjective sleepiness and focus in contrast to older adults. This may well not have been a problem regarding the Seclidemstat Autophagy present outcomes, as our study sample consists of an extremely homogeneous age group, but rather an issue regarding comparability in between studies investigating light exposure with subjects of distinctive age groups. Future research need to for that reason address this challenge with regards to general interindividual and age-related variations in light-responsiveness to gain much more insight into the interaction among the everyday present artificial light consumption and our inner clock. four. Materials and Techniques 4.1. Participants 33 healthful male subjects (mean age: 21.70, standard deviation: 1.91, range: 185 years) have been recruited and examined at the University of Salzburg among October 2019 and December 2020. The present outcomes extend our already published preliminary information of a subset of 14 participants [64]. All subjects have been no cost of medication, non-smokers and reported no history of drug abuse, night-shift functioning, neurological or psychiatric disease. Additional, they had been right-handed, showed no above typical caffeine consumption (i.e., 3 cups of coffee, or 1 power drink each day) and weren’t intense chronotypes (defined as subjects with raw sum-scores under 31 or above 69) as outlined by the German version from the morningness-eveningness questionnaire [65]. For the whole study period sleep habits had been monitored with wrist actigraphy (Cambridge Neurotechnology Actiwatch, CamNTech Ltd., Cambridge, England) and sleep diaries (“morning/evening protocol”; adapted version of Saletu and colleagues [66]) to assure a regular sleep-wake cycle. Participants have been remunerated with either one hundred Euros and 16 h obviously credit for participation in scientific research or with 50 Euros and 24 h certainly credit. All participants provided written informed consent. The study was approved by the neighborhood ethics committee and performed in accordance with the most current v.