Abstract
Reports of various forms of mentation were collected at the wake-sleep transition from 25 female students. Each of 3-min polygraphical records prior to awakening was classified into five EEG-EOG stages, reflecting the variation of standard sleep stages and slow eye movement (SEM) : W (standard stage W with low SEM), D1 (standard stage W with high SEM), D2 (standard stages W and 1 with high SEM), D3 (standard stages 1 and 2 with high SEM) and S (standard stages 2 and 3+4 with low SEM). Sleep perception and sleepiness increased as a function of EEG-EOG stage, and SEM was found to directly relate to sleep perception. Visual imagery was reported at all stages except for stage W, and half of the reports were impressed as dreaming or hallucination and were associated with underestimate of the really elapsed time. The reports of thought showed a wide variety of contents at stages Dl and D2, covering the future-, reality-, and past-oriented ones, whereas it turned into more vague with the content-forgetting predominant at stages D3 and S. Such a chaotic thinking often occurred together with visual imagery.
