Perception of Being Awake During Sleep Tied to Normal Brain Function, Not Just Insomnia

Recent research reveals that the experience of perceiving oneself as awake during sleep is linked to typical brain activity, rather than solely indicating insomnia or sleep disturbances. This study, led by Carlotta Schneider from the University of Geneva, involved 30 healthy individuals and 30 patients diagnosed with insomnia disorder, all subjected to controlled sleep laboratory settings.

During the experiment, participants underwent two nights of adaptation followed by a night where they were awakened up to 12 times during non-REM sleep through vibrating bracelets. Afterwards, they were asked to report whether they believed they had been asleep or awake during these interruptions. Interestingly, about half of the awakenings resulted in reports of being asleep, and the other half of being awake, regardless of whether the participant was healthy or had insomnia.

Further analysis showed that high-frequency brain activity, which reflects arousal levels, was associated with reports of wakefulness during sleep in both groups. Notably, despite patients with insomnia reporting subjective sleep problems, their objective sleep measurements and actual sleep-wake perceptions did not differ significantly from healthy controls.

This research supports the emerging concept of a sleep-wake continuum—meaning that wake-like brain activity can persist during sleep, blurring traditional boundaries between these states. Importantly, sleep–wake regulatory systems appear to function normally in insomnia patients when assessed with current standard measures, suggesting that their sleep complaints may develop through sustained cognitive, emotional, and behavioral processes over time.

These insights have significant implications for understanding and treating sleep disorders. They suggest that many patients, after excluding organic sleep issues, may improve their sleep through cognitive-behavioral therapy for insomnia (CBT-I), which is now considered the first-line treatment. Pharmacological options remain available but are typically limited to short-term use due to potential side effects, tolerance, and dependence.

Ongoing studies are investigating the sleep-wake continuum further, exploring subgroups of patients, and expanding the use of non-pharmacological therapies. Ultimately, recognizing the persistence of wake-like brain activity during sleep could lead to more tailored and effective treatments for insomnia and related sleep disturbances.