Partial REM-sleep deprivation increases the dream-like quality of mentation from REM sleep and sleep onset.

Study Objectives: Sleep onset (SO) is cognitively and physiologically similar to rapid eye movement (REM) sleep, supporting the notion that REM sleep-related processes are 'covertly' active at this time. The objective was to determine if SO mentation is sensitive to REM sleep deprivation.

Design: Two-group cross-sectional design; sleep recordings for 3 nights.