SUMMARYThe effects of the vertical inversion of the visual field on REM sleep mental activity were examined to explore the potential involvement of this activity in information processing. In a first experiment, four male subjects slept in the laboratory for two sessions of 6 consecutive nights: 2 adaptation nights, 2 nights of polysomnography and 2 nights of dream collection. During the days preceding Nights 3, 4, 5, 6 of each session, the subjects wore glasses which, during the second session, completely inverted (rotation of 180°) their visual field. In a second experiment with four other male subjects, the order of conditions was reversed and the experimental condition (visual inversion) was introduced twice. The data of the two experiments were combined. Overall, following visual inversion, there were significant increases in the proportion of dreams containing motor and visual difficulties (P<0.005), misfortunes (P<0.05) and dreamer confusion (P<0.05) and a decrease in dreamer participation (P<0.05).Only 4 of the 8 subjects experienced incorporations of the inverted visual field into their dreams and they tended to perform better on two of three tests of adaptation to the visual inversion. The observed changes in dreams are consistent with the notion of continuity between waking and dreaming since they appear to reflect the waking preoccupation and psychological state associated with visual inversion.
dream content, REM sleep, visual inversionThe possibility that REM sleep is involved in information inversion. In this situation, which was studied notably by processing and memory consolidation has received considerable Kö hler (1964), subjects must reorganize their visual perception theoretical and empirical attention (for example see reviews by and motor coordination. Zimmerman et al. observed that McGrath & Cohen 1978; Smith , 1993. Many studies subjects wearing inverting prisms during daytime experienced have indeed reported increases in REM sleep percentages and a significant increase in REM sleep during adjacent nights eye movement density following enhanced learning conditions compared to pre and post experimental nights. However, (for examples, Smith & Lapp 1986 De Koninck et al. Allen et al. (1972) were not able to replicate the observations 1989). While many authors have considered the dreaming of Zimmerman et al. (1970) when they controlled for activity associated with REM sleep as a component of restriction of the visual field, weight of the inverting prisms information processing (for example Greenberg 1981), and day activities. Other factors were not controlled, however. empirical examination of dream content following intensive For example, some of their subjects experienced stress and learning conditions is lacking. In a recent report, the results nausea which could explain the lack of increase in the of two studies of the effects of inversion of the visual field on amount of REM sleep following visual inversion. Two studies REM sleep were presented (De Koninck & Prévost 1991).wi...