Sleep, REM

Eye movements (with closed lids) were studied in a group of highly hypnotizable experimental subjects experienced in self-hypnosis, and compared with a random sample of control subjects that had never been hypnotized and were low in waking suggestibility. Approximately half the experimental subjects rolled their eyes upwards to a greater extent when hypnosis was induced than during eye closure while awake. In some subjects eye flutter occurred during hypnosis, but not in the awake condition.

Characteristic changes in eye movements occurred during meditation with closed eyes in a proportion of subjects experienced in TM. The most common changes were an increase in slow, large-amplitude, 'rolling' eye movements and a concomitant decrease in rapid, low-amplitude, 'jerky' eye movements. Much variation occurred between individuals, however, some subjects showing no differences between TM and non-meditation. Any changes that occurred were not necessarily constant for the whole recording period nor consistent between sessions.

The minute eye movements of 4 sleeping subjects were studied with a piezo-electric strain-gauge transducer. The frequency and amplitude of ocular microtremor activity diminished during sleep. Activity increased after auditory stimulation and with the appearance of a K complex in the EEG. The ocular microtremor activity also increased with the onset of rapid eye movement (REM). Low amplitude 'micronystagmoid' movements were observed at intervals throughout sleep. In contrast to the changes observed during sleep, ocular microtremor activity did not diminish during hypnosis.

Visual imagery, hypnosis, creativity, dreams, and "imagination" have all been linked conceptually by theoreticians of various schools to an increased influence of right hemispheric processes compared with left hemispheric processes. This paper reviews empirical studies that have addressed the issue of whether there is an increased activation or efficiency of right hemispheric processes during imagery, hypnosis, rapid eye movement sleep, and dreaming. Overall, there is considerable evidence supporting the notion of increased right hemispheric activation in imagery.

A series of 33 patients with combined (injurious) sleepwalking, sleep terrors, and rapid eye movement (REM) sleep behavior disorder (viz. "parasomnia overlap disorder") was gathered over an 8-year period. Patients underwent clinical and polysomnographic evaluations. Mean age was 34 +/- 14 (SD) years; mean age of parasomnia onset was 15 +/- 16 years (range 1-66); 70% (n = 23) were males.