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Internal deliberations (focused thoughts) and endogenous percepts (hallucinations) vary in a reciprocal manner across the states of waking and sleep, paralleling changes in regional brain activation. As subjects go from waking through sleep onset to NREM sleep and then to REM sleep, they report progressively more hallucinoid imagery and progressively less thinking. We have investigated whether this reciprocity in cognition between NREM and REM is maintained throughout the night. To do so, we analyzed 229 REM and 165 NREM reports collected with the Nightcap sleep monitoring system from 16 participants in their homes over 14 nights. The reports were scored for the presence of hallucinations and directed thinking by external judges. As predicted, hallucinations were more frequent in REM than in NREM for each segment of the night, and directed thinking was more frequent in NREM in the first 5 h of the night. Late in the night, directed thinking was equally infrequent in NREM and REM. At the same time, hallucinations increased within both NREM and REM as the night progressed, whereas directed thinking decreased in NREM and remained at a stable, low level in REM. These findings suggest that a reciprocal shift in focused thinking and hallucinating is a general property of cognitive activity across the wake–sleep cycle. Biological evidence supports the hypothesis that these cognitive changes are governed by specific state regulatory and neurocognitive processes at several levels of the brain. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop an inexpensive, simplified home monitoring system for prescreening certain sleep complaints and for long-term home-based experiments. Four subjects slept in the laboratory for 3-4 nights. In addition to a standard polysomnogram, piezoelectric ceramic transducers were attached to both hands, both feet, and over the right eyelid. The sleep from 2 nights of each subject was staged according to the standard criteria. The limb transducers identified major and minor body shifts and were used to signal possible state changes. The data from the eye movement sensor was used to develop a REM-state algorithm. Using this algorithm, REM and NREM sleep were identified with 92% (SD=0.091) and 91% (SD=0.076) accuracy, respectively. The ultimate goal is to have a bedside device programmed with the algorithm that would either store information or score the data on-line for waking, NREM, and REM states. We conclude that a system monitoring eye movements and major body shifts is a promising approach to an economical and accurate home recording system. [ABSTRACT FROM AUTHOR]

Presents the abstracts of papers presented to the 9th Annual Meeting of the Association for the Psychophysiological Study of Sleep, held in Boston, Massachusetts on March 20-23, 1969. Psychological correlates of phasic and tonic events during sleep; Phasic events and mentation during sleep; Dream content and physiological functioning; Time-related changes in physiological characteristics of rapid eye movement.