Cardiovascular responses to dreamed physical exercise during REM lucid dreaming.

Previous studies have demonstrated intriguing psychophysiological correspondences when lucid dreamers carried out specific tasks during lucid dreams (e.g., eye movements and EMG activities). But only a few studies have investigated cardiovascular changes during dreamed physical activities. This study tests the hypothesis that physical activity (performing squats) carried out in a lucid dream increases cardiovascular parameters in the sleeping body. Therefore, 5 proficient lucid dreamers experienced with the eye-signaling method during lucidity spent 2 to 4 nonconsecutive nights in a sleep laboratory. Instructed to carry out specific tasks (counting and performing squats) while lucid dreaming, the participants reported becoming lucid and signaling in 11 REM periods recorded. Fourteen complete lucid dream tasks were verified by eye signaling. The results showed a statistically significant increase of heart rate between the preexercise and exercise periods and the postexercise period. The results for respiration rate were less clear. Even though respiration rate during the exercise period was higher than during the pre- and postexercise period, statistical significance was only found for the second comparison. Overall, the results support the hypothesis that lucidly dreamed motor action causes increases at the level of peripheral effectors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lucid dreaming frequency and change blindness performance.

There are reports of lucid dreaming being cued by the recognition that a dream event is bizarre from the point of view of waking life. However, for dreams in general, there is a lack of ability to notice or question bizarre occurrences. A waking-life analog of this inability is here proposed to be change blindness. In change blindness tasks, a prominent alteration to a photograph occurs repeatedly, but it is rare for these changes to be spotted immediately. It was hypothesized that lucid dreamers would perform better on change blindness tasks than would nonlucid dreamers. Contrary to the hypothesis, individuals who reported having lucid dreams more than once per month (n = 13), occasional lucid dreamers (n = 13), and nonlucid dreamers (n = 12) were found not to differ significantly on performance on 6 change blindness tasks. How the usually proficient unconscious detection of errors during waking life is disabled during dreams remains to be determined, but it does not seem from the results here to have a simple relationship with the waking-life phenomenon of change blindness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dreamed movement elicits activation in the sensorimotor cortex

Since the discovery of the close association between rapid eye movement (REM) sleep and dreaming, much effort has been devoted to link physiological signatures of REM sleep to the contents of associated dreams [1-4]. Due to the impossibility of experimentally controlling spontaneous dream activity, however, a direct demonstration of dream contents by neuroimaging methods is lacking. By combining brain imaging with polysomnography and exploiting the state of "lucid dreaming," we show here that a predefined motor task performed during dreaming elicits neuronal activation in the sensorimotor cortex. In lucid dreams, the subject is aware of the dreaming state and capable of performing predefined actions while all standard polysomnographic criteria of REM sleep are fulfilled [5, 6]. Using eye signals as temporal markers, neural activity measured by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS) was related to dreamed hand movements during lucid REM sleep. Though preliminary, we provide first evidence that specific contents of REM-associated dreaming can be visualized by neuroimaging.     

Virtual reality training of lucid dreaming

Metacognitive reflections on one''s current state of mind are largely absent during dreaming. Lucid dreaming as the exception to this rule is a rare phenomenon; however, its occurrence can be facilitated through cognitive training. A central idea of respective training strategies is to regularly question one''s phenomenal experience: is the currently experienced world real, or just a dream? Here, we tested if such lucid dreaming training can be enhanced with dream-like virtual reality (VR): over the course of four weeks, volunteers underwent lucid dreaming training in VR scenarios comprising dream-like elements, classical lucid dreaming training or no training. We found that VR-assisted training led to significantly stronger increases in lucid dreaming compared to the no-training condition. Eye signal-verified lucid dreams during polysomnography supported behavioural results. We discuss the potential mechanisms underlying these findings, in particular the role of synthetic dream-like experiences, incorporation of VR content in dream imagery serving as memory cues, and extended dissociative effects of VR session on subsequent experiences that might amplify lucid dreaming training during wakefulness.This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation''.     

Theory of Mind in Dreaming: Awareness of Feelings and Thoughts of Others in Dreams.

If the awareness of what others are thinking and the ability to attribute feelings to others characterizes both waking and dreaming consciousness, it suggests that a social species like man has a state-independent need for a theory of mind; that is, an ability to know that others have feelings. The authors performed 2 studies, the first of which consisted of 35 participants who submitted 320 dream reports containing more than 1,200 dream characters and the second consisted of 24 participants who submitted 151 dream reports with 543 dream events. Participants reported that as subjects in their own dreams they were aware that their dream characters had feelings and thoughts about them. This finding shows that awareness of what others are feeling is a robust aspect of consciousness that is maintained despite the changed chemistry and changed activation patterns of the brain's neuronal connections during dreaming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Association of lucid dreaming frequency with Stroop task performance.

Lucid dreaming involves the attentional skill of having metacognition about the dreamer's state of consciousness at the same time as being engaged in the dream scenario. A combination of two levels of cognition also occurs in the incongruent condition of the Stroop task, where there is interference between the attentional demands of a relatively difficult (color naming) and an easy (reading) task. It was thus hypothesized that frequent lucid dreamers would perform better on the Stroop task than would nonlucid dreamers. Individuals who reported having lucid dreams more than once per month (n = 15) were found to be significantly faster on the incongruent condition of the Stroop task than were occasional lucid dreamers (n = 15) or nonlucid dreamers (n = 15). The groups did not differ on the standard colored nonword control condition. Continuity in attentional ability between waking and dreaming cognition was thus found. This continuity may counteract the psychophysiologically dominant and possibly evolutionarily selected lack of self-awareness in dreams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream emotions, waking emotions, personality characteristics and well-being--A positive psychology approach.

The study aimed to discover whether personality characteristics and waking emotions relate to dreaming emotions. There were 123 participants, ranging in age from 17 to 82 years. It was hypothesized that participants with significant positive emotional trait and state ratings in waking life would experience more positive dreams. Data collection utilized diaries and questionnaires, including Hartmann's Boundary Questionnaire, IPIP Emotional Stability Scale, Staats' Hope Scale, Adult Dispositional Hope Scale, and the Positive and Negative Affect Schedule to assess personality and attitudinal characteristics. Participants recorded and rated their waking and dream emotions over a 3-week period. Median correlations between corresponding waking and dream emotions were .58 for positive emotions and .47 for negative emotions. There were also low, but significant correlations between some personality characteristics and participants' tendency to experience positive or negative emotions in dreams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dreaming correlates of alexithymia among sleep-disordered patients.

Increasing evidence supports the clinical view that alexithymia is associated with disturbed dreaming. However, a consistent, replicable pattern of relationships between alexithymia and different dreaming components has not yet been identified. Groups of sleep-disordered outpatients (N = 580; 46.0 ± 13.2 years) and nonclinical controls (N = 145; 22.9 ± 4.2 years) were administered the Toronto Alexithymia Scale (TAS-20) and a 14-item Dreaming Questionnaire. Sleep diagnoses were assessed from polysomnography and clinical histories following the American Academy of Sleep Medicine classification system. The Dreaming Questionnaire was reduced by principal-components analysis to a 3-factor solution that distinguishes nightmare distress, dream recall, and dream meaning items. Factor coefficients were correlated with TAS total score and TAS subscales while age was controlled as a covariate. TAS total score was found to correlate positively with nightmare distress and negatively with dream recall for both clinical and nonclinical groups and for both men and women considered separately. TAS total score also correlated negatively with dream meaning for nonclinical participants. TAS subscales were differentially correlated with the 3 dream factors: difficulty identifying feelings (DIF) with increased nightmare distress, difficulty describing feelings (DDF) with decreased dream recall and externally oriented thinking (EOT) with decreased dream meaning. With some exceptions, these patterns were obtained independently for clinical and nonclinical groups and for men and women within these groups. Findings suggest a consistent and replicable pattern of relationships between alexithymia and dreaming components that implicates processes regulating emotion during both wakefulness and dreaming, for example, affect distress, expressive anxiety, and openness to experience. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Lucid Art and Hyperspace Lucidity

This article explores nonrepresentational, multidimensional lucid dreaming and its parallel imagery in modern art paintings. Developed from a series of successive qualitative experiments on art and lucid dreaming, the study brings together phenomenological and narrative approaches to reveal a relationship between imagery in a particular lucid dream experience (Hyperspace Lucidity) and a particular type of modern art painting (Lucid Art). This article attempts to open new dialogues for investigation of the interconnection between the dreaming mind and art.     

Investigation of dream reports after transcranial direct current stimulation (tDCs) during slow wave sleep (SWS)

Despite being a prominent feature of REM sleep, dreams have also been reported from NREM sleep. Neuroimaging studies have revealed regional patterns of brain activation and deactivation during REM and NREM sleep, with frontal and posterior parietal cortices implicated as brain regions involved in dreaming. From our recent stage 2 study it was revealed that tDCs of these brain regions during this stage of sleep resulted in an increase in reported dream imagery. Thus, the aim of this study was to investigate the effect of simultaneous anodal and cathodal tDCs applied to the right posterior parietal and frontal cortex (respectively) during SWS on dream recall. After 60 s of continuous SWS, participants were administered either tDCs, low tDCs, or blank control, followed by a 60 s delay period to confirm SWS before waking the participant for dream report collection. These conditions were administered in a counterbalanced order across the night. Analyses revealed no significant difference between conditions in the three dream measures. However, an analysis of visualizable nouns to total words revealed a significantly higher ratio in the low tDCs condition compared to the tDCs condition. It was concluded that tDCs had no appreciable effect on reported dream imagery. However, such findings are preliminary as they are from a research protocol which is in the process of refinement with more definitive results expected in future. Thus, further studies should now investigate the application of tDCs using improved methodologies and to other cortical regions implicated in the process of dreaming.

     

EEG Correlates of Dream Recall in Depressed Outpatients and Healthy Controls

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 wakefiilness, 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 larger. 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.     

Dreaming and unilateral brain lesions: A multiple lesion case analysis.

Lesions causing cessation of dreaming are thought to be more frequently left hemispheric than right hemispheric. However, reports of this phenomenon have not excluded epileptic cases and have not reported handedness, etiology of the lesion, lesion location, comorbidity, gender, age, and so forth, on a case-by-case basis. Some authors were also concerned about aphasia being a cause of dream loss and its lateralization, but they never measured its impact statistically. The present investigation reviews cases of post lesion dream cessation that answered to strict criteria for testing hemispheric lateralization and the effect of aphasia on it. In the 31 subjects, left hemisphere lesions were significantly more frequent than right, as predicted, but the left hemisphere lesions were very often associated with aphasia. Nonaphasic cases of total dream loss had lesions equally often in the right and in the left hemisphere. It is proposed that aphasia deprives patients of a second dream-encoding system, which is important enough to induce amnesia of dream occurrence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological correlates of lucid dreaming.

The main goal of the present study was to explore electrophysiological differences between lucid and nonlucid dreams in REM sleep. Seven men and four women experienced in lucid dreaming underwent polysomnographic recordings in the sleep laboratory on two consecutive nights. EEG signals were subjected to spectral analysis to obtain five different frequency bands between 1 and 20 Hz. Lucidity was determined by both subjective dream reports and eye-movement signals made by the subjects in response to light stimuli indicating a REM period. The main discrimination factor between lucid and nonlucid dreaming was found in the beta-1 frequency band (13-19 Hz), which in lucid dreaming was increased in both parietal regions. The ratio of frontal to parietal beta-1 activity was 1 to 1.16 in nonlucid and 1 to 1.77 in lucid dreaming. A tendency towards the greatest increase was observed in the left parietal lobe (P3), an area of the brain considered to be related to semantic understanding and self-awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Definitions of Dream: A Paradigm for Comparing Field Descriptive Specific Studies of Dream

A single definition for dreaming is most likely impossible given the wide spectrum of fields engaged in the study of dreaming, and the diversity in currently applied definitions. Many studies do not specify a definition, yet results are likely to be comparable only when comparable definitions of the topic are used. The alternative is to develop a classification system organizing the multiplicity of definitions for dream. A dream should not be exclusively defined as a non-conscious electrophysiologic state. Dreaming is, at least in part, a mental experience that can be described during waking consciousness. Definitions for dreaming should be utilized in research and discussion which address the various axes which define dreaming: Wake/sleep, Recall, and Content.     

Lucid Dreaming and Personality: A Replication.

This article reports an investigation of personality variables that may be associated with the reporting of lucid dreaming. The present study confirmed that lucid dreamers, both frequent and occasional (n = 26), were more internal on J. Rotter's (1966) locus of control measure and scored higher on J. Cacioppo and R. Petty's (1982) need for cognition measure than did nonlucid dreamers (n = 24). Frequent but not occasional lucid dreamers were more field independent on H. A. Witkin et al.'s (1971) Group Embedded Figures Test than the nonlucid dreamers. Need for cognition, internality on locus of control, and field independence all correlated with each other. The results can be argued to show a continuity between styles of waking and dreaming personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Video game play and lucid dreams: Implications for the development of consciousness.

The improvement of various cognitive skills associated with video game play has been well documented; however, the development of consciousness implications have not been considered. In the present study several potential indicators of consciousness development, including and especially lucid dreaming frequency, were examined as a function of video game play. In the first study, high video game players were more likely to report lucid dreams, observer dreams, and dream control when dream recall frequency and motion disorientation during play were controlled. There were no similar differences in other consciousness development indices. In the second study, a slightly different pattern of results occurred because of respondents all being frequent players. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of a two-week reflection-intention training program on lucid dream recall.

Previous research in the field of lucid dreams has produced several techniques which are claimed to be a means of inducing lucid dreams, but there have been only a small number of reported studies which have evaluated their effectiveness. The present study investigated the effects of one of the most promising of these, the reflection-intention technique, which is specifically designed to increase the frequency of dream and lucid dream recall. The sample here consisted of 20 participants whose frequencies of normal dream recall and lucid dream recall were recorded before, during and after a two week training program by using a dream questionnaire and a dream journal: A one-way repeated measures analysis of variance showed a significant increase in both dream recall frequency (F2,38 = 22.09, p2,38 = 5.96, p     

Review of The Mind at Night: The New Science of How and Why We Dream.

In this article I review "The Mind at Night: The New Science of How and Why We Dream," written by Andrea Rock. To begin with this book is an exciting journey through modern dream research. Scientific facts, which are skillfully explained, are complemented by personal accounts of well-known researchers in the field obtained through interviews. The diversity of the themes addressed in the book (e.g., sleep and memory, animal research, imaging studies, dream content analysis, consciousness research, creativity, and lucid dreaming) clearly shows the extensive "detective work" the author has accomplished. The major problem I had--as a researcher in this field--was the structure, or the lack of structure, within the book. Because of the way the book is organized, I decided to structure this review along the following themes: REM sleep, REM sleep and dreaming, biology of dreaming, dream content findings, and the integration of dream research into cognitive neuroscience in general. Despite the lack of structure of the book, Andrea Rock has written a wonderful book about modern dream research that is stimulating for researchers as well as for interested lay persons. I recommend it to everyone who is interested in dream research, the old question of the mind-body relationship, or understanding consciousness in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lucid Dreaming Treatment for Nightmares: A Series of Cases

Goal of this series of cases was to investigate lucid dreaming treatment for nightmares. Hypotheses were that lucid dreaming treatment would decrease nightmare frequency and state/trait anxiety, and improve the quality of sleep. Eight participants received a one-hour individual session, which consisted of lucid dreaming exercises and discussing possible constructive solutions for the nightmare. Nightmare frequency and sleep quality were measured by a sleep questionnaire, anxiety was measured by the Spielberger State and Trait Anxiety Inventory. At the follow-up two months later the nightmare frequency had decreased, while the sleep quality had increased slighty. There were no changes on state and trait anxiety. Lucid dreaming treatment seems to be effective in reducing nightmare frequency, although the effective factor remains unclear.