Dreaming without REM sleep.

To test whether mental activities collected from non-REM sleep are influenced by REM sleep, we suppressed REM sleep using clomipramine 50mg (an antidepressant) or placebo in the evening, in a double blind cross-over design, in 11 healthy young men. Subjects were awakened every hour and asked about their mental activity. The marked (81%, range 39-98%) REM-sleep suppression induced by clomipramine did not substantially affect any aspects of dream recall (report length, complexity, bizarreness, pleasantness and self-perception of dream or thought-like mentation). Since long, complex and bizarre dreams persist even after suppressing REM sleep either partially or totally, it suggests that the generation of mental activity during sleep is independent of sleep stage.

[Dreams in normal and pathological aging]. / Le rêve au cours du vieillissement normal et pathologique.

Although most of scientific knowledge in dream research is based on young adult studies, this article provides a review of the effects of normal and pathological aging on dream psychology. It starts with preliminary comments about epistemological and methodological principles of dream research, its singularities in aged persons, and the modifications of sleep physiology with age. The whole literature agrees that dream recall progressively decreases from the beginning of adulthood - not in old age - and that dream reports become less intense, perceptually and emotionally. This evolution occurs faster in men than women, with gender differences in the content of dreams. The chronological modifications could be explained partly by changes in lifestyle and attitude towards dreams in early adulthood, but mainly by modifications of sleep physiology, particularly the decrease and qualitative changes of rapid eye movement (REM) sleep. Dreams have usually little subjective importance in the mental life of aged persons. However, working with dreams can be a valuable tool for psychotherapy in the aged. According to the few existing data, patients suffering degenerative dementia dream much less than healthy aged persons. In Alzheimer's disease, this could be linked to the decrease of REM sleep, and atrophy of associative sensory areas of the cerebral cortex. Most studied aspects of dreaming in degenerative cognitive disorders are REM sleep behavior disorders, and nightmares induced by cholinesterase inhibitors. More studies are needed to better characterize the evolution of dreams with age, particularly studies performed in sleep laboratory.

Awakening from sleep.

Awakening is a crucial event for the organism. The transition from sleep to waking implies physiological processes which lead to a new behavioural state. Spontaneous awakenings have varying features which may change as a function of several factors. The latter include intrasleep architecture, circadian phase, time awake, age, or disordered sleep. Despite its clear theoretical and clinical importance, the topic of awakening (in humans) has received little attention so far. This contribution focuses on major issues which relate to awakening from both basic (experimental) and clinical research. Recent knowledge on neurophysiological mechanisms is reported. The experimental data which provide in the human suggestions on the regulation of awakening are discussed, mainly those concerning sleep architecture and homeostatic/circadian factors also in a life-span perspective, since age is a powerful factor which may influence awakening. Clinical contributions will examine two main sleep disorders: insomnia and hypersomnia. Daytime functioning is shown in insomniac patients and compared to other pathologies like sleep apnea. A final section evokes links between some types of night waking and psychological factors.