Participants
sleep disorders, pain
SYNDROME
All participants provided written informed consent before screening and study-related activities. This study was a part of a more extensive research on the effects of sleep deprivation> Next to the impact of sleep deprivation on driving, effects on pain thresholds were assessed. Because of the influence of the ovarian cycle on pain thresholds, initially, only men were invited to participate. For the latter assessment, only men between 23 and 35 years of age were invited to participate in the study. Only experienced drivers, defined as participants having a valid driving licence for at least five years and having, on average, a self-reported annual mileage of at least 3000 km, were included in the study. No history or presence of sleep disorders was allowed. Participants had to remain in the same time zone as the Netherlands at least seven days before the first visit and during the trial period. Additionally, participants showing signs of Simulator Sickness Syndrome before or during a screening of the simulated driving sessions were not eligible to participate. See 