ensomme

Ensomme is a term used in sleep research and cognitive science to describe a transitional state between wakefulness and sleep. It denotes a spectrum in which conscious awareness can coexist with neurophysiological signs of sleep, typically occurring during the hypnagogic phase before sleep onset or in brief micro-sleeps. The concept is often discussed in relation to dream imagery, memory processing, and altered perception that do not fully constitute either wakefulness or established sleep stages.

Etymology and history of use are informal. The word resembles a blend of a French derivation related to sleep (sommeil) and a prefix suggesting being “in” something. The idea of a half-awake, dream-like state has appeared in sleep literature and popular science discussions since the early 21st century, but ensomme as a labeled category has not achieved universal consensus or formal diagnostic status.

Characteristics and measurement. Researchers describe ensomme through a combination of subjective reports and physiological markers. Common features include brief episodes of vivid imagery, slowed mental processing, and EEG patterns showing increased theta activity with reduced beta activity. Because there is no single agreed-upon diagnostic criterion, studies vary in how they define and identify ensomme, contributing to ongoing debate about its reliability and boundaries.

Applications and reception. Some researchers explore ensomme to understand dream recall, lucid dreaming training, or cognitive processing during sleep onset. Others view it as a conceptual niche within broader discussions of sleep-wake transitions. Critics note that without standardized definitions, the term remains exploratory and not widely used in clinical practice.

See also: hypnagogia, hypnopompia, sleep inertia, lucid dreaming.