veillesommeil

Veillesommeil is a French-language neologism that combines veille (the state of being awake) and sommeil (sleep). It refers to the boundary or interaction between wakefulness and sleep and is used to describe the transition period around sleep onset as well as the broader dynamics of wakefulness and rest in daily life. The term is not part of a formal taxonomy in sleep science; rather, it appears in scholarly and popular writings as a descriptive concept for how arousal declines and sleep pressure increases, or how wakefulness can intrude during the early sleep period.

In scientific contexts, veillesommeil is related to topics such as sleep onset, hypnagogia, sleep inertia, and circadian rhythm alignment or misalignment. It also figures in discussions of how modern behavior—late-night screen use, shift work, and irregular schedules—affects the balance between waking and sleeping.

Methods studying wake-sleep balance include polysomnography, actigraphy, and sleep diaries, along with subjective assessments of sleepiness. Discussions of veillesommeil emphasize the importance of regular sleep schedules, adequate exposure to light during the day, and wind-down routines to facilitate a smoother transition from wakefulness to sleep.

See also: sleep, circadian rhythm, insomnia, sleep deprivation, chronobiology.