Consciousness in non-REM-parasomnia episodes

Area of Science:

• Neurology
• Sleep Medicine
• Cognitive Neuroscience

Background:

• Sleepwalking and related parasomnias originate from incomplete awakenings during non-rapid eye movement (non-REM) sleep.
• Previous research presents conflicting views on consciousness during these episodes, describing them as either unconscious or involving dream-like experiences.

Purpose of the Study:

• To comprehensively characterize the spectrum of consciousness and environmental interaction during non-REM sleep parasomnia episodes.
• To explore the variability in subjective experiences, including awareness, hallucinations, and memory.

Main Methods:

• In-depth interviews were conducted with 35 adult patients diagnosed with non-REM sleep parasomnias.
• Qualitative data analysis focused on reported levels of consciousness, sensory perception, emotional states, and amnesia during episodes.

Main Results:

• Consciousness levels during episodes were highly variable, both within and between individuals.
• Reported experiences ranged from automatic behaviors (36%) to complex conscious states (65%) involving delusions, hallucinations (53%), impaired insight (77%), negative emotions (75%), and amnesia (30%).
• Patients often described these episodes as "awake dreaming," with altered perception of their surroundings.

Conclusions:

• Non-REM sleep parasomnias exhibit a graded spectrum of consciousness, sensory disconnection, and amnesia.
• These episodes share core features with dreams, making them a valuable model for studying consciousness, dreaming, and sleep-related sensory disconnection.