Episodic thought distinguishes spontaneous cognition in waking from REM and NREM sleep.
Consciousness and cognition January 1, 2022 Benjamin Baird, Mariel Kalkach Aparicio, Tariq Alauddin et al. 17 citations
Spontaneous episodic thoughts about the past and future are common during waking but rarely occur during N2 or REM sleep. Analysis of thought reports from 138 participants who underwent experience-sampling while awake and serial awakenings during sleep shows that waking spontaneous thought frequently includes autobiographical planning with a strong bias toward the future. In contrast, dreaming sleep states rarely feature such mental time travel. This suggests that human consciousness differs substantially across the sleep-wake cycle in how it typically engages with episodic past and future events.