Circadian rhythms in physiology and behavior are modulated by external factors such as light or temperature. We studied whether self-selected office lighting during the habitual waking period had a different impact on alertness, cognitive performance and hormonal secretion in extreme morning and evening chronotypes (N = 32), whose preferred bed- and wake-up times differed by several hours. The self-selected lighting condition was compared with constant bright light and a control condition in dim light. Saliva samples for hormonal analyses, subjective ratings of alertness, wellbeing, visual comfort and cognitive performance were regularly collected. Between the self-selected and the bright, but not the dim lighting condition, the onset of melatonin secretion in the evening (as marker for circadian phase) was significantly different for both chronotypes. Morning chronotypes reported a faster increase in sleepiness during the day than evening chronotypes, which was associated with higher cortisol secretion. Wellbeing, mood and performance in more difficult cognitive tasks were better in bright and self-selected lighting than in dim light for both chronotypes, whereas visual comfort was best in the self-selected lighting. To conclude, self-selection of lighting at work might positively influence biological and cognitive functions, and allow for inter-individual differences.

• MeSH
• afekt MeSH
• bdění MeSH
• cirkadiánní rytmus fyziologie   účinky záření   MeSH
• dospělí MeSH
• hormony metabolismus   MeSH
• hydrokortison metabolismus   MeSH
• kognice * MeSH
• lidé MeSH
• melatonin metabolismus   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• osvětlení * škodlivé účinky   MeSH
• pozornost * MeSH
• sliny metabolismus   MeSH
• spánek fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hormony MeSH
• hydrokortison MeSH
• melatonin MeSH