Sleep during an Antarctic summer expedition: new light on "polar insomnia".

Sleep complaints are consistently cited as the most prominent health and well-being problem in Arctic and Antarctic expeditions, without clear evidence to identify the causal mechanisms. The present investigation aimed at studying sleep and determining circadian regulation and mood during a 4-mo Antarctic summer expedition. All data collection was performed during the continuous illumination of the Antarctic summer.

Emotion regulation mediates the relationship between personality and sleep quality.

Objective: Despite a long history of interest in personality as well as in the mechanisms that regulate sleep, the relationship between personality and sleep is not yet well understood. The purpose of this study was to explore how personality affects sleep.

Design: The present cross-sectional study, based on a sample of 1291 participants with a mean age of 31.

Individual differences in subjective circadian flexibility.

The aim of this study was to evaluate individual differences in the subjective flexibility of the circadian system in a community sample, with respect to age, gender, chronotype, and sleepiness perceptions. An online questionnaire containing the Circadian Type Inventory, the Composite Scale of Morningness, the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale was administered. In addition, participants performed a visuo-verbal judgment task to determine time-of-day variations in estimated sleepiness.