Human Sciences Press, Inc., New York City
Dreaming Volume 8, Number 2, June 1998
Special Issue: Psychobiology of Dreaming
Special Issue Editors: Tore A. Nielsen, Ph.D. and Roseanne Armitage, Ph.D.
Publication Patterns in Dream Research: Trends
in the Medical and Psychological Literatures
Tore A. Nielsen and Anne Germain
The Prevalence of Sleep Paralysis among Canadian
and Japanese College Students
Kazuhiko Fukuda, Robert D. Ogilvie, Lisa Chilcott, Ann-Marie Vendittelli, and Tomoka Takeuchi
Topographical EEG Mapping in a Case of Recurrent
Antonio L. Zadra and Tore A. Nielsen
A Laboratory Study of Sleep and Dreaming in
a Case of Asperger's Syndrome
Roger Godbout, Cybčle Bergeron, Emmanuel Stip, and Laurent Mottron
Sleeping Dreams, Waking Hallucinations, and
the Central Nervous System
Mark W. Mahowald, Sharon R. Woods, and Carlos H. Schenck
Dream Content in Patients with Narcolepsy:
EEG Correlates of Dream Recall in Depressed
Outpatients and Healthy Controls
Aaron Rochlen, Robert Hoffmann, and Roseanne Armitage
Effects of Somatosensory Stimulation on
Dream Content in Gymnasts and Control Participants: Evidence of Vestibulomotor
Adaptation in REM Sleep
Anny Sauvageau, Tore A. Nielsen, and Jacques Montplaisir
Tore A. Nielsen and Anne Germain
Publication Patterns in Dream Research: Trends in the Medical and Psychological Literatures
Dreaming: Journal of the Association for the Study of Dreams. Vol 8(2) 47-58, Jun 1998.
The annual rate of journal publications is a pertinent index of a scientific field's prosperity. In the present study, annual publication rates were calculated for the field of dream research using both medical (Index Medicus, MEDLINE) and psychological (PsychINFO) reference databases. A composite profile from the medical database spanning 111 years revealed very similar changes in publishing levels following the release of Freud's (1958/1900) The Interpretation of Dreams and the publication in Science of Aserinsky and Kleitman's (1953) article on dreaming and "rapid, jerky eye movements." In both cases, the peak year occurred 15 years after release of the work, and the peak was followed by a precipitous 3-year drop and then a slow and yet variable decline. In the more recent case, the peak level (reached in 1969) dropped (during 1970-1972) by about half and has continued a slow decline to the present day. As is the case with basic sleep research, this level of activity does not keep pace with either (1) global growth in scientific publishing or (2) growth in related sleep disciplines, particularly, sleep disorders and chronobiology. The psychological database confirms many features of the medical database profile—but is advanced by 1 year, i.e., a publishing peak in 1968, a drop from 1969-1971, and a slow decline until 1980. In this case, however, 1981 marks the beginning of a period of renewed growth that has endured to the present. This divergence between the two publishing profiles may reflect the field's shift from psychophysiological to cognitive and dream analytic approaches since the early 1980s.
Kazuhiko Fukuda, Ph.D. Robert D. Ogilvie, Ph.D., Lisa Chilcott,
Ann-Marie Vendittelli, and Tomoka Takeuchi, Ph.D.
The Prevalence of Sleep Paralysis among Canadian and Japanese College Students
Dreaming: Journal of the Association for the Study of Dreams. Vol 8(2) 59-66, Jun 1998.
Although sleep paralysis had been treated as one of the symptoms of narcolepsy, recently it has become recognized as occurring frequently in normal individuals. However, among the few published studies that have examined sleep paralysis, there are great discrepancies in its reported prevalence. These discrepancies could be attributed to differences in survey methods, to the description of the symptom employed in each study, or to the race or culture of the research participants. We administered a questionnaire, with equivalent Japanese and English forms, to 86 Canadian and 149 Japanese university students. Although the reported prevalence of sleep paralysis was almost the same (Canada: 41.9%, Japan: 38.9%), the characterization of the phenomenon differed greatly between the two samples. Over 55% of the Canadian and only about 15% of the Japanese students regarded the experience as 'a kind of dream.' This difference may be one of the reasons for the varying prevalence noted in previous studies. Although many Japanese students (40.5%) and a very small number of Canadians (3.5%) usually prefer the supine position while sleeping, the majority of both groups (Canada: 57.9%, Japan: 83.8%) reported that, during the episodes of sleep paralysis, they found themselves in the supine position.
Key Words: sleep paralysis; hypnagogic hallucinations; cultural differences
Sleep terrors are characterized by marked CNS arousal and typically occur during stage 3-4 sleep within the first NREM cycle. Studies of the EEG during sleep terrors suggest that delta power and synchrony in the EEG may be important physiological markers of sleep terror presence and intensity. An EEG mapping study was undertaken with a single participant who experienced three sleep terror episodes in the laboratory. A one-minute section of EEG was sampled immediately prior to the onset of each of the three sleep terrors. Similar EEG sections were taken from 10 healthy sex- and age-matched controls. The sleep terrors and control (normative) data were then compared topographically with z-scores (z-mapping). The z-maps indicated that all three sleep terrors contained more total and delta power in central and frontal areas than the control EEG sections. Moreover, relative delta power in these areas for the three sleep terrors was proportional to the subjective intensity of the episode. Although this pre-arousal EEG pattern may be related to ongoing slow-wave sleep mentation that may sometimes trigger sleep terror episodes, its functional significance remains an open question. The results demonstrate the utility of EEG mapping for the quantification of brain activation during sleep terror attacks and suggest that discrete activity profiles are identifiable for different types of dreaming-related arousal.
Key Words: EEG Mapping, Arousal, Sleep Terrors, Parasomnias
Asperger's Syndrome (AS) is a pervasive developmental disorder whose continuity with High-Functioning Autism is still a matter of debate. Clinical observations suggest that patients with AS may present the same sleep disorders as autistic patients, including difficulties in initiating and maintaining sleep as well as poor dream recall. We recorded the sleep of a 25-year-old male patient with AS for two nights using a full EEG montage and compared the second night to that of a group of normal participants. We found low levels of slow wave sleep (SWS: stages 3 + 4), high levels of stage 1, and a large number of awakenings. The organization of REM sleep was unremarkable, including normal REM density. Analyses of phasic EEG events revealed a very low incidence of sleep spindles and a normal number of K-complexes over bilateral frontal and central EEG leads. In order to collect dream reports, the patient was awakened three times over two nights following at least 15 minutes of REM sleep in each case. On each occasion the patient was not aware of any mental activity happening just prior to awakening. These observations are discussed with regards to the connections that may exist between EEG sleep spindle activity, selective attention, and the capacity to generate a dream report.
Key Words: autism, rapid eye movements, sleep spindles, thalamus, Fahr's disease.
Mark W. Mahowald, M.D., Sharon R. Woods, M.D., and Carlos H. Schenck,
Sleeping Dreams, Waking Hallucinations, and the Central Nervous System
Dreaming: Journal of the Association for the Study of Dreams. Vol 8(2) 89-102, Jun 1998.
Consciousness is now considered a primary function and activity of the brain itself. If so, consciousness is simply the brain's interpretation and integration of all the information made available to it at any given time. On the assumption that the brain is active across all states of being (wakefulness, REM sleep, and NREM sleep), this article proposes that dreaming and hallucinations represent variations on the same theme. Under usual circumstances during wakefulness, the brain ignores internally generated activity and attends to environmental sensory stimulation. During sleep, dreaming occurs because the brain attends to endogenously generated activity. In unusual settings, such as sleep-deprivation, sensory deprivation, or medication or drug ingestion, the brain attends to exogenous and endogenous activities simultaneously, resulting in hallucinations, or wakeful dreaming. This concept is supported by numerous neurologic conditions and syndromes that are associated with hallucinations.
Key Words: dreams, hallucinations, REM sleep, NREM sleep, consciousness
Dream Content in Patients with Narcolepsy: Preliminary Findings
Dreaming: Journal of the Association for the Study of Dreams. Vol 8(2) 103-107, Jun 1998.
The present study investigated dream recall and dream content in patients with narcolepsy. Compared to healthy controls, patients with narcolepsy reported higher dream recall frequency and more negatively toned and bizarre dreams, confirming earlier findings.
Key Words: narcolepsy, bizarreness
Aaron Rochlen, B.A., Robert Hoffmann, Ph.D. and Roseanne Armitage,
EEG Correlates of Dream Recall in Depressed Outpatients and Healthy Controls
Dreaming: Journal of the Association for the Study of Dreams. Vol 8(2) 109-123, Jun 1998.
The present study explored EEG correlates of dream recall in 17 symptomatic, unmedicated depressed patients and in 19 healthy adults. EEG segments from the last 30 minutes of sleep, from the five minutes following morning awakening, and the absolute difference between sleep and waking EEG were contrasted between the two groups of participants during successful dream recall and during no recall. Period amplitude analysis was used to quantify EEG frequencies. Increased high-frequency beta incidence in the right hemisphere and amplitude in both hemispheres during sleep were associated with dream recall in both patient and control groups. Depressed patients also showed higher delta amplitude in both hemispheres during sleep associated with recall, but this effect did not reach significance. With regard to the changes between sleep and wakefulness, a smaller change in right hemisphere beta and delta incidence characterized successful recall in healthy controls. By contrast, those with depression showed recall success when the sleep/wake shifts in right hemisphere beta and delta incidence were large. Recall failure was characterized by small EEG shifts from sleep to wakefulness in the depressed group. The same effects were observed for beta and delta amplitude measures, except that healthy controls showed a large shift in delta amplitude in the sleep-wake transition during successful recall but not during recall failure. Recall in those with depression was associated with a dramatic shift in left hemisphere delta amplitude. These findings provide support for Koukkou and Lehmann's (1983, 1993) state-shift hypothesis of dream recall in healthy controls (except for left hemisphere delta amplitude) but not in the depressed. It appears that in order to recall a dream, depressed patients must undergo larger shifts in brain activity and perhaps a different pattern of reorganization of EEG frequencies than controls. This finding may account for the low rates of recall reported previously in this clinical group.
Key Words: EEG, dream recall, depression, sleep
Somatosensory stimulation of the leg muscles in REM sleep appears to perturb virtual orientation in dream experiences. According to our model of vestibulomotor adaptation (Sauvageau, Nielsen, & Montplaisir, 1996), the dreaming mind attempts to compensate for such destabilizing stimulation by increasing eye movement activity or by modifying dream content, among other possible reactions. Effective compensation may be more easily achieved by participants who are adapted to the disruptive stimulation or who possess highly developed vestibulomotor skills. To examine this possibility, we studied the effects of somatosensory stimulation on the dreams of 6 gymnasts and 6 control participants aged 9 to 16 years. Results provide some support for the expectations that 1) imposed somatosensory information is processed by the central nervous system in REM sleep, 2) unilateral stimulation induces an upset in virtual orientation, 3) gymnasts are more resistant to these disruptive effects of stimulation than are control participants, and 4) because of long-term adaptation, the dream content of gymnasts does not differ markedly from that of controls. Though preliminary and in need of replication, the findings are compatible with the notion that the developed vestibular skills of gymnasts protects them to some extent from the effects of a disruptive somatosensory stimulus during sleep.
Key Words: adaptation, somatosensory stimulation, REM sleep, dreams, eye movements
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