Frequency of lucid dreaming in a representative German sample

Lucid dreams occur when a person is aware that he is dreaming while he is dreaming. In a representative sample of German adults (N = 919), 51% of the participants reported that they had experienced a lucid dream at least once. Lucid dream recall was significantly higher in women and negatively correlated with age. However, these effects might be explained by the frequency of dream recall, as there was a correlation of .57 between frequency of dream recall and frequency of lucid dreams. Other sociodemographic variables like education, marital status, or monthly income were not related to lucid dream frequency. Given the relatively high prevalence of lucid dreaming reported in the present study, research on lucid dreams might be pursued in the sleep laboratory to expand the knowledge about sleep, dreaming, and consciousness processes in general.     

Muslims dreaming of Christians,Christians dreaming of Muslims: Images from Medieval dream interpretation

Medieval Muslims attached great importance to learning the hidden meanings of dreams which, they believed, might disclose the true character of the dreamer and others or predict the future. The popularity of dream interpretation in the Islamic Middle East is reflected in the large number of manuals devoted to the subject. They provide a valuable picture of common information, misinformation and social attitudes on a wide range of topics, including Christianity and Christians. By contrast, Christian dream interpreters were frequently regarded with suspicion in the Byzantine Empire and very little of their work has survived. The present study looks at views of each other's faith in the work of two major interpreters, one Muslim and one Christian, from the tenth to eleventh centuries, an influential period in a very conservative tradition where interpretations would commonly be repeated for centuries in many different compilations.     

Testing the involvement of the prefrontal cortex in lucid dreaming: A tDCS study

Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with the second one. According to the participants’ self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed.     

The multiplicity of dreams: cognitive-affective correlates of lucid, archetypal, and nightmare dreaming

This preliminary research is the first to compare lucid, nightmare, and archetypal-mythological dreams on dimensions important in previous research on each. A first study of 100 subjects showed all three forms significantly correlated with each other and with estimates of dream recall. In a second study, 41 subjects were selected from the above on the basis of relative specialization in each dream form, with a control group equally high on dream recall. Here, the lucid and archetypal dreamers tended to separate themselves from nightmare sufferers on the basis of high imaginativeness, proclivity to waking mystical experience, spatial/analytic skills, and physical balance. It appears that the intensification of dreaming is expressed positively or negatively, depending on variations in these cognitive dimensions.     

Conscious dream synthesis as a method of learning about dreaming: a pedagogic experiment

Stimulated by Freud's comments on the unique perspectives offered by "building up dreams by synthesis," the authors applied this idea to the St. Louis Psychoanalytic Institute's introductory course on the psychology of dreaming. Each student was assigned the task of purposefully and consciously synthesizing a dream, utilizing certain assigned information and meeting the specified criteria. In the use of this device, it was anticipated that the conscious active effort required to duplicate the usually passively experienced processes of dreaming and the unconscious dream work would lead to a deeper understanding and appreciation of the dream.     

Conception and dream material during psychoanalysis

A dream announcing her conception and describing in symbolic terms physiological processes associated with the early stages of pregnancy was reported by a female analysand 4 days after she and her husband had engaged in intercourse for the purpose of procreation. The manifest content of the dream and the associations to it are described. The assumption that conception, ordinarily a subliminal stimulus, was a somatic stimulus in this situation is explored. It is suggested that three special factors—the patient's exceptional sensitivity to internal sensations, her strong motivation to conceive, and a contributory awakening stimulus— may have made it possible for her to perceive her conception.     

Cognitive and emotional processes during dreaming: a neuroimaging view

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation.     

Cognitive asymmetry and dreaming: lack of relationship

The present study investigated the relationship between cognitive laterality and dream recall, dream characteristics, and eye movement density in rapid eye movement (REM) sleep. Fifty-two right-handed males, age 20-30 years, were tested on a six-test battery of which three tests measure right hemisphere function and three tests measure left hemisphere function. Based on their performance, 14 subjects were selected for a sleep laboratory study. Each spent 3 experimental nights in the laboratory during which they were awakened from REM sleep for dream reports. Dream reports were scored for bizarreness, emotions, visual elements, and overall "dreamlike" versus "thoughtlike" character. Subjects were awakened from 123 REM periods, of which 96 yielded positive dream reports (78.04%). Neither the rate of recall nor the four evaluation scores were correlated with the laterality scores that were constructed from the six-test battery. Eye movement density during REM sleep was significantly positively correlated with the total performance of the two hemispheres. These results do not support the alleged lateralization of dreaming. In agreement with recent reports in the literature, it is concluded that dreaming cannot be seen as a "right hemisphere" function.     

Recognition of alphabetic characters during voluntary eye movements

In this paper we reconsider the question of vision during eye movements using a novel display procedure which guarantees that the eye was not stopped at any time during the eye movement. The results of our experiment lead us to conclude that true “saccadic suppression,” is a most elusive phenomenon. Furthermore, a brief analysis of the optics of the eye movement suggests that a substantial amount the elevation of visual threshold during eye movements can be attributed to simple retinal smear if one acknowledges the dominating importance of edge effects in visual threshold measurements.     

Strengths and weaknesses of McNamara's evolutionary psychological model of dreaming

This article includes a brief overview of McNamara's (2004) evolutionary model of dreaming. The strengths and weaknesses of this model are then evaluated in terms of its consonance with measurable neurological and biological properties of dreaming, its fit within the tenets of evolutionary theories of dreams, and its alignment with evolutionary concepts of cooperation and spirituality. McNamara's model focuses primarily on dreaming that occurs during rapid eye movement (REM) sleep; therefore this article also focuses on REM dreaming.     

Further explorations of perceptual speed abilities in the context of assessment methods, cognitive abilities, and individual differences during skill acquisition

Measures of perceptual speed ability have been shown to be an important part of assessment batteries for predicting performance on tasks and jobs that require a high level of speed and accuracy. However, traditional measures of perceptual speed ability sometimes have limited cost-effectiveness because of the requirements for administration and scoring of paper-and-pencil tests. There have also been concerns about the validity of previous computer approaches to administering perceptual speed tests (e.g., see Mead & Drasgow, 1993). The authors developed two sets of computerized perceptual speed tests, with touch-sensitive monitors, that were designed to parallel several paper-and-pencil tests. The reliability and validity of the tests were explored across three empirical studies (N = 167, 160, and 117, respectively). The final study included two criterion tasks with 4.67 and 10 hours of time-on-task practice, respectively. Results indicated that these new measures provide both high levels of reliability and substantial validity for performance on the two skill-learning tasks. Implications for research and application for computerized perceptual speed tests are discussed.     

State-dependent thinking: a comparison of waking and dreaming thought

Thinking is known to be state dependent but a systematic study of how thinking in dreams differs from thinking while awake has not been done. The study consisted of analyzing the dream reports of 26 subjects who, in addition to providing dream reports also provided answers to questions about their thinking within the dream. Our hypothesis was that thinking in dreams is not monolithic but has two distinct components, one that is similar to wake-state cognition, and another that is fundamentally different. We found that cognition within a dream scenario was similar to that of wake-state cognition, but that thinking about the scenario itself was deficient and very different than wake-state thinking.     

A computational account of dreaming: Learning and memory consolidation

A number of studies have concluded that dreaming is mostly caused by random signals because “dream contents are random impulses”, and argued that dream sleep is unlikely to play an important part in our intellectual capacity. On the other hand, numerous functional studies have suggested that dream sleep does play an important role in our learning and other intellectual functions. Specifically, recent studies have suggested the importance of dream sleep in memory consolidation, following the findings of neural replaying of recent waking patterns in the hippocampus. This study presents a cognitive and computational model of dream process that involves episodic learning and random activation of stored experiences. This model is simulated to perform the functions of learning and memory consolidation, which are two most popular dream functions that have been proposed. The simulations demonstrate that random signals may result in learning and memory consolidation. The characteristics of the model are discussed and found in agreement with many characteristics concluded from various empirical studies.     

Optic aphasia, optic apraxia, and loss of dreaming

A 47-year-old man with a left temporo-occipital infarct in the area of the posterior cerebral artery is presented. The neuropsychological examination did not reveal aphasia or gross mental deficits. The patient presented with alexia without agraphia, color agnosia, but few visual perceptual deficits. The main impairment was in confrontation naming; he was incapable of naming objects and pictures, not from lack of recognition (excluding visual agnosia) but from lack of access to the appropriate word (optic aphasia). The patient also exhibited a deficit in the evocation of gesture from the visual presentation of an object (optic apraxia) and a difficulty in "conjuring up" visual images of objects (impaired visual imagery) and loss of dreams. The fundamental deficit of this patient is tentatively explained in terms of visuoverbal and visuogestural disconnection and a deficit of mental imagery.     

Use of parafoveally visible characters during the reading of Chinese sentences

Chinese readers' use of parafoveal character previews was examined. In Experiment 1, the preview of target characters consisted of targets or of graphemically similar, homophonic, or dissimilar characters. Each preview was replaced with the corresponding target when the eyes reached the target location. Oculomotor measures revealed preview benefits for targets, for graphemically similar characters, and for homophonic characters. Experiment 2 showed that parafoveal preview of graphemically similar characters yielded benefits primarily when they shared the phonetic radical with their targets. The phonological relationship between previewed radicals and subsequently viewed targets was ineffective. Chinese character processing thus involves the initial use of orthographic information from the phonetic radical and the activation of the character's phonological form.     

The unwelcome child and his dreams: reconceptualization of dreaming in trauma

Based on the concepts of Sándor Ferenczi on trauma and vincularity, the author examines the operation of the mechanisms of dreaming in the processing of early traumatic situations and their clinical utilization. The difference is established between dreams of “repetition”, which lack dream imagery and contain a great amount of anguish, consisting of bodily sensations which may last on awakening, and the “secondary dream” with imagery, into which the first type can be transformed when the capacity of the psychic apparatus to process the traumatic situation is increased through therapeutic work. This “secondarization” of the repetitive dream has a traumatolytic effect, allowing the patient to reach psychoanalytically the mechanisms and mental states prevailing in the traumatic situation, through the mechanism of dream autorepresentation described by Silberer. In some cases, as illustrated in the clinical material, it is possible to anticipate the event of episodes of somatic disease before they become clinically evident.?The detailed analysis of dreams in patients with these characteristics is presented and discussed.