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Motor area activation during dreamed hand clenching: A pilot study on EEG alpha band
Abstract
In a single participant physiological responses to dreamed motor performance in REM lucid dreams (LD) were studied. Electroencephalographic (EEG) alpha power over motor areas (C3, Cz, C4) has been recorded while the participant performed specific motor tasks (hand clenching vs. counting) in a LD. The lucid dreamer marked those dream events by pre-arranged eye movement patterns evident in the recorded electrooculogram (EOG). Results showed that EEG alpha power over bilateral motor areas decreased while the lucid dreamer executed left or right hand clenching in contrast to dream counting, which supports the hypothesis that motor performance during lucid dreaming involves the same cortical areas as during waking performance. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
... As is well known, dream research is characterized by a notable limitation: the existence of a temporal gap between dream generation and the moment in which the dream is reported. In the attempt to overcome this "asynchrony", some authors have used the eye-signaling technique, i.e., pre-decided sequences of intentional eye movements during dreaming [2][3][4], to reveal the exact moment of dream production. However, while this method is successfully applied to lucid dreams, it is not applicable to the "traditional" mental sleep activity. ...
... Recently, it was suggested that the EEG frontal theta activity during REM sleep might modulate dysphoric dreams, as nightmares [89], altering the function of the amygdala and increasing abnormal oneiric activity in PTSD patients [165]. The presence of higher slow theta activity (2)(3)(4)(5) in the frontal and central areas has been observed in a sample of nightmare recallers compared to controls. Moreover, Spoormaker and colleagues [166] reported that the suppression of REM sleep would impair fear extinction and that the percentage of REM sleep obtained in consequence of fear extinction can predict decreased arousal as measured by skin conductance [167]. ...
Sleep significantly changes across the lifespan, and several studies underline its crucial role in cognitive functioning. Similarly, mental activity during sleep tends to covary with age. This review aims to analyze the characteristics of dreaming and disturbing dreams at different age brackets. On the one hand, dreams may be considered an expression of brain maturation and cognitive development, showing relations with memory and visuo-spatial abilities. Some investigations reveal that specific electrophysiological patterns, such as frontal theta oscillations, underlie dreams during sleep, as well as episodic memories in the waking state, both in young and older adults. On the other hand, considering the role of dreaming in emotional processing and regulation, the available literature suggests that mental sleep activity could have a beneficial role when stressful events occur at different age ranges. We highlight that nightmares and bad dreams might represent an attempt to cope the adverse events, and the degrees of cognitive-brain maturation could impact on these mechanisms across the lifespan. Future investigations are necessary to clarify these relations. Clinical protocols could be designed to improve cognitive functioning and emotional regulation by modifying the dream contents or the ability to recall/non-recall them.
... In a similar vein, Jausovec and Jausovec (2000) found increased desynchronization in the upper alpha band during a picture completion task in contrast to a verbal creative ideation task. Consistent with these studies, the current finding of alpha power decreases at parieto-occipital sites supports the assumption that creative ideation in the figural domain (in this study predominantly during the stage of idea generation), is associated with various directly task-specific and sensory based visual mental operations, like visual imagery (Marks and Isaac, 1995;Petsche et al., 1997), mental rotation, spatial transformation, and imaginary manipulation of objects (Pfurtscheller et al., 1994;Riecanský and Katina, 2010;Sauseng et al., 2005;Williams and Rippon, 1995), as well as the imagination of movements (Erlacher et al., 2003;Pfurtscheller et al., 2006). In line with this, the originality of the drawings was associated with process related power decreases at centro-temporal sites from idea generation to idea elaboration (and at the same time power increases at frontal positions), which might further indicate the importance of motor imagery (i.e., imagine drawing a picture; Erlacher et al., 2003;Pfurtscheller et al., 2006) for creative ideation in the figural domain, especially during the stage of idea elaboration. ...
... Consistent with these studies, the current finding of alpha power decreases at parieto-occipital sites supports the assumption that creative ideation in the figural domain (in this study predominantly during the stage of idea generation), is associated with various directly task-specific and sensory based visual mental operations, like visual imagery (Marks and Isaac, 1995;Petsche et al., 1997), mental rotation, spatial transformation, and imaginary manipulation of objects (Pfurtscheller et al., 1994;Riecanský and Katina, 2010;Sauseng et al., 2005;Williams and Rippon, 1995), as well as the imagination of movements (Erlacher et al., 2003;Pfurtscheller et al., 2006). In line with this, the originality of the drawings was associated with process related power decreases at centro-temporal sites from idea generation to idea elaboration (and at the same time power increases at frontal positions), which might further indicate the importance of motor imagery (i.e., imagine drawing a picture; Erlacher et al., 2003;Pfurtscheller et al., 2006) for creative ideation in the figural domain, especially during the stage of idea elaboration. This interpretation is also supported by recent fMRI studies, reporting the involvement of motor imagery (i.e., activation of premotor areas) during figural creativity (Aziz-Zadeh et al., 2013) as well as during music improvisation (Bengtsson et al., 2007), which, taken as a whole, nicely corresponds to the notion that imagination is highly important during creative ideation in general (Benedek, 2018;Finke et al., 1996;Jung et al., 2016). ...
This study investigated EEG activity in the upper alpha band during the well-known Picture Completion Task of the Torrance Test of Creative Thinking (TTCT), a widely used creative ideation task in the figural domain. The application of a sophisticated computerized version of the TTCT facilitating the online assessment and digitalizing of participant's drawings allowed to separate two central stages of the creative ideation process (i.e., idea generation and idea elaboration). During idea generation, the participants’ task was to generate an initial draft of an original and creative completion of the presented abstract lines and figures of the TTCT. During idea elaboration, the participants were required to mentally improve the originality of the initially generated idea/draft. Creative ideation in this figural task was generally associated with comparatively strong desynchronization of upper alpha power over parietal and occipital sites, indicating high visual/figural processing demands. Interestingly, the stage of idea elaboration was accompanied by a relative increase of upper alpha power at parietal and occipital sites compared to the stage of idea generation, indicating heightened top-down processing demands. Furthermore, task performance was associated with relative increases of upper alpha power at frontal sites and relative decreases at centro-temporal sites from the stage of idea generation to idea elaboration. This association suggests the importance of increased inhibitory control over stimulus-based bottom-up information and motor imagery in order to achieve more creative outputs. Taken together these findings add to the relevant literature in that they a) extend research on the relationship between EEG alpha activity and creativity to the figural domain, and b) support a multistage view of creative ideation, involving cognitive control and mental imagery as important components of creativity.
... Furthermore, dreamed movements seem to yield neural activity patterns similar to the ones that are activated when the same movements are carried out physically, which was demonstrated in an EEG study (Erlacher, Schredl, & LaBerge, 2003) as well as in studies using fMRI/ NIRS . ...
... Erlacher and Schredl (2008b) suggest that physically executed and dreamed movements share the same neural mechanisms. Recent findings support this assumption: Correspondences between dreamed and physical movements were found for autonomic responses (Erlacher & Schredl, 2008a), neural activation Erlacher, Schredl, & LaBerge, 2003), and temporal aspects . Based on these findings, it can be assumed that lucid dream practice in general could lead to performance enhancement. ...
In sports practice a well-established method is mental practice which is, for example, applied in elite sports to intensify practice and to offer additional practice sessions when opportunities for physical practice are limited (Erlacher, 2007). It is also used on other areas, such as surgery and music. There is a special way of mentally rehearsing movements without physical activity: in our dreams (Stumbrys, 2014). In so called lucid dreams, the dreamer is consciously aware that he or she is dreaming and can thus decide to carry out actions deliberately (Schredl & Erlacher, 2004). In a survey by Erlacher, Stumbrys, and Schredl (2011–2012) it was shown that within a German sample 9% of all athletes who had lucid dreams used the lucid dream state to practice motor skills, for most of them with a positive impact on physical performance. Furthermore, anecdotal examples and previous qualitative and quantitative research has demonstrated that practicing movements in lucid dreams is possible and could possibly even improve performance in waking life for (overview see e.g. Stumbrys, 2014). However, the effectiveness of lucid dream practice had not yet been studies in a controlled sleep laboratory setting. The aim of this investigation was to further explore the effectiveness of lucid dream practice, and to derive practical implications for athletes. A particular goal was to assess the effectiveness of lucid dream practice using signal verified lucid dreams in a sleep laboratory. Furthermore, an extensive qualitative interview study was intended to explore the potential as well as phenomenal experience and difficulties of lucid dream practice. A similar study was planned for musicians to investigate if lucid dream practice can also be applied in this area. Since a requirement for lucid dream practice is to actually achieve lucidity in the dream state, another goal of this investigation was to test two ways of lucid dream induction by external stimulation. The first chapter of this dissertation gives an introduction into mental practice, including evidence that mental practice can improve physical performance in sport and other areas, such as music education. The second chapter first provides some information on sleep and dreams, followed by characteristics and applications of lucid dreams. Chapter three addresses lucid dream induction. The attached book chapter includes a detailed description and evaluation of induction techniques and discusses research problems. Then a study on lucid dream induction through visual and tactile stimulation is presented (Paper 1). Chapter four contains the most important contributions of this investigation: After introducing lucid dream practice, a sleep laboratory study is outlined which investigated the effectiveness of lucid dream practice using a dart throwing task (Paper 2). Then an extensive qualitative study is presented in which 16 athletes were interviewed about their experiences with lucid dream practice (Paper 3), followed by a smaller pilot study in which the potential of lucid dream practice for musicians was explored (Paper 4). Finally, in the last chapter the findings of all studies are summarized and discussed, deriving implications for both sports practice and future research.
... Studies from lucid dream research (for an overview, see LaBerge, 2000) have demonstrated a strong correlation between lucidly dreamed actions and physiological measurements. Correlations can be found for eye movements (LaBerge, Nagel, Dement, & Zarcone, 1981), brain activation measured by electroencephalography (e.g., Erlacher, Schredl, & LaBerge, 2003), limb twitches measured by electromyography (EMG; e.g., Fenwick et al., 1984), and cardiovascular parameters (e.g., LaBerge, Greenleaf, & Kedzierski, 1983). Two lucid dream studies (LaBerge & Dement, 1982;LaBerge et al., 1983) investigated the correlation between cardiovascular parameters and activities in lucid dreams. ...
... The results from our study support the hypothesis that motor activity in lucid dreams also shares neural mechanisms that are responsive to motor programming, as suggested by the studies on motor imagery (Jeannerod, 2001). Taking into consideration the results from this study and the results from the pilot studies from Erlacher et al. (2003) and LaBerge (1990) showing a relation between lucid dreamed action and actual motor activity leads to the hypothesis that training of motor skills in the simulated environment of dreams is very likely to improve waking performance (Erlacher, 2005;Erlacher & Schredl, 2008). For mental training in wakefulness (for overviews, see Driskell, Copper, & Moran, 1994;Feltz & Landers, 1983), it has been shown that simulation of specific exercises improved performance for a wide variety of motor tasks. ...
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) 2012 APA, all rights reserved)
... Cela permet à l'expérimentateur de vérifier objectivement la survenue d'un rêve lucide et d'isoler le début et la fin du rêve sur l'enregistrement neurophysiologique. Ce signal, confirmé a posteriori par le rapport subjectif au réveil de la survenue d'un rêve lucide, fournit un marqueur temporel qui ouvre une nouvelle méthode d'étude de la physiologie du SP, permettant, par exemple, d'étudier les corrélats physiologiques du contenu mental des rêveurs (DODET et al., 2015 ;ERLACHER et al., 2003 ;LABERGE, 1990 ;OUDIETTE et al., 2018). ...
Les expériences de notre nuit sont souvent décrites comme des îlots d'activité mentale, internement générées dans un océan d'inconscience. En sous-texte de cette vision se cachent deux pré-supposés que le sommeil lent est un modèle d'inconscience et que le traitement sensoriel du monde extérieur en sommeil paradoxal ne peut être qu'inconscient. Dans cette thèse, nous avons voulu tester ces pré-supposés avec une approche empruntant à trois littératures complémentaires : celle de la conscience, celle du sommeil sain et pathologique et celle de la philosophie de l'esprit. Dans une première étude nous avons mis en évidence l'existence de "blackout' de nuit : une absence total de rappel de contenu du couche au lever dans l'hypersomnie Idiopathique. Nous pensons que notre démonstration de l'existence du phénomène de blackout est intéressante car elle permet, par contraste, de mettre en évidence l'existence d'une expérience minimale de la nuit, comme les philosophes l'avaient suggéré. Dans deux autres études nous avons montré la capacité de patients narcoleptiques (lucides ou non) à traiter l'extérieur pendant des siestes en utilisant comme réponses les muscles de leurs visages. Cela suggère qu'un traitement conscient dans le sommeil peut avoir lieu en sommeil paradoxal chez ces patients. L'ensemble de ce travail de thèse invite à penser que l'idée selon laquelle on perd conscience pendant que l'on dort serait à réévaluer. En effet, une réelle perte de conscience dans le sommeil, si elle existe, pourrait être plutôt transitoire et négligeable face à la fabuleuse pluralité des processus qui se déroulent en son sein.
... Por ejemplo, en uno de los estudios, antes de que los pacientes durmiesen, se les indicó que cuando comenzasen a soñar lucidamente (donde por supuesto estaban durmiendo) hiciesen movimientos oculares predefinidos (ya que es la única función motora que tiene control durante el sueño) y luego mientras estaba en el sueño lúcido, que apretasen los puños de la mano izquierda y derecha sucesivamente. El resultado fue sorprendente, viendo como, a pesar de ser personas que están desconectadas del mundo, los soñadores lúcidos eran capaces de indicar mediante movimientos oculares que estaban soñando, apretando los puños como se les había indicado (Erlacher et al., 2003). El patrón de actividad cerebral era casi idéntico al patrón durante la vigilia y, además, se ha comprobado que durante el sueño lúcido se puede fortalecer el motor de la memoria. ...
During this research, called Prototypes and archetypes of the representation of sleep paralysis: an approach from art, we analyzed, as its title indicates, the different artistic prototypes and archetypes that have emerged around a neurological sleep disorder known as sleep paralysis. This parasomnia takes place during the transition from sleep to wakefulness, responding to common symptoms that cause great suffering and fear to those afflicted by it, primarily through visual sensory hallucinations.
Due to the limited and scarce information on this sleep disorder in the field of artistic research, a medical approach has been followed in the first and second chapters, accompanied by a discussion of the relevant psychological aspects, which will enable a better understanding of the anthropological field that surrounds it. This allows us to enter in the third chapter, where the cultural evolution of this parasomnia in the anthropological context is investigated through the examination of the mythology surrounding the incubus and the succubus, both of which are figures that are frequently associated with sleep paralysis. Their respective interpretation and interiorization as real beings will provide, through the association of ideas and the collective imagination, different social behavioral values to people regarding their experience with sleep paralysis. In the fourth chapter, an exhaustive analysis of prototypes and archetypes arising from the artistic representation of sleep paralysis is presented, focusing on the study of the work The Nightmare (1781) by Henry Füssli. A categorization and methodological chronology of different works ranging from the 18th century to the present day is discovered, which allows us to understand and study their analogous corresponding representation in art. In the fifth chapter, it is provided a reflection On the artistic representation and interpretation of different concepts associated with sleep paralysis, such as identity, memory and the emotion of fear, which has forwarded our understanding of this sleep disorder. At the same time, a study specifically designed for this project involved the collection of testimonies of people who have experienced sleep paralysis, in order to study their visual patterns in hallucinations from their descriptions. In the sixth and last chapter, a new perspective on the representation of sleep paralysis is proposed through the creation of subjective visual works (based on the testimonies) using photographic techniques.
The methodology used to undertake this research involved the study and analysis of ancient medical and cultural treatises, such as the Persian manuscript Hidayat by Akhawayni Bohkari from the 10th century, The Discoverie of Witchcraft (1584) by Reginald Scot, the story The Night-Mare (1664) by Isbrand Van Diermerbroeck, the essay An essay on the incubus, or nightmare (1753) by John Bond and The Nightmare (1931) by Ernest Jones, among others. In additioninterviews were taken from contemporary artists who currently represent sleep paralysis very similar and were assembled in a compendium. Furthermore, an analytical and statistical study was also carried out, based on interviews of people who have suffered from this sleep disorder accompanied by a collection of written testimonies submitted through a web page created specifically for this artistic study.
One of the main objectives was to develop a codified study of the myths and legends in different cultures and countries, and to understand their symbolic representation based on their popular imagery and the existing tradition in the category of the monstrous and the figure of the incubus in art. Specifically, we tracked the above mentioned work The Nightmare by Füssli, a work whose influence pertains to this day, being the most representative prototype and archetype of sleep paralysis. These research outputs will allow us to reflect on, to recreate and to question the existing representation of sleep paralysis in art until our days. The final objective is to approach the subjective representation of the experience of sleep paralysis, breaking with the prototype and archetype created over the years. To this end, new patterns of representation will be proposed through the author`s artistic creation based on the collected testimonies, in order to create a visual guide that serves as a means of understanding a society that has no prior experience with sleep paralysis.
As a final conclusion, the interdisciplinary nature of this research has allowed us to understand the mythology and beliefs associated with sleep paralysis, which enables the identification and designation of possible prototypes and archetypes in the artistic representation of this parasomnia, marked by a powerful collective imagination. The artistic work presented here has created novel prototypes and archetypes of sleep paralysis, which greatly advances our understanding of this experience. As it is shown, this work is considerably better understood when is accompanied by the description of testimonies, as it connects a communication code between the text and the image. Nevertheless, despite the fact that a new proposal for the representation of sleep paralysis in art is emerging, the timeless value of the representation of Füssli’s The Nightmare is confirmed here. With this study, and with the resulting artistic works, we are able to approximate the experience of this parasomnia to a public that was unaware of it, which also reveals how the imagination operates on a collective and personal level, since it is built on each individual with components that are inherited culturally and transmitted and expressed through art.
... Somewhat paradoxically, such reactivation can result in profound state changes at both the psychological and physiological level; merely dreaming that one 'critically questions reality' can indeed result in that critique being performed authentically. Since volitional motor activity performed within one's dreams can recruit the same cortical regions as when waking [5,6], it stands to reason that volitional thought processes performed within one's dreams may also be capable of operating by this logic. In other words, reflecting upon the authenticity of one's environment while asleep can produce the necessary state changes in neurological activity as to generate lucidity as an explicit psychological endpoint. ...
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'.
... Despite the general muscular atonia during REM sleep, corresponding EMG activity can also be measured in distal muscle groups (Fenwick et al., 1984;LaBerge et al., 1981). Further, motor actions in lucid dreams appear to activate the same regions of the sensorimotor cortex as motor actions in wakefulness (Dresler et al., 2011;Erlacher, Schredl, & LaBerge, 2003). The duration of actions carried out in lucid dreams correspond with the duration of actions in wakefulness (Erlacher, Schädlich, Stumbrys, & Schredl, 2014). ...
Despite the fact that lucid dream research and transpersonal psychology have common grounds, overlapping interests and a great potential to contribute to each other, the two fields over the recent decades evolved rather separately. The present article aims to renew the mutual dialogue by introducing the recent advancements of lucid dream research to the transpersonal community, discussing the relevance and providing some common directions for the future. It is argued that lucid dreaming is a transpersonal experience in itself, which can be mapped and explored, and also used as a gateway to facilitate further transpersonal and mystical experiences. Lucid dreaming can be used therapeutically as a tool for transpersonal psychotherapy or as a spiritual practice. Finally, it may help to gain some insights into the nature of consciousness. Combining empirical findings from lucid dream research with transpersonal frameworks might be a fruitful approach to advance the understanding of farther reaches of human dream nature.
... Furthermore, lucid dreamers can not only signal to indicate that they are aware that they are dreaming, but they can also make the eye movement signals to time-stamp the start and end of experimental tasks performed during lucid dreams (LaBerge, 1990). By providing objective temporal markers, this technique has opened up a new method for studying the psychophysiology of REM sleep, allowing, for example, investigations into the neural correlates of dreamed behaviors (e.g., Dresler et al., 2011;Erlacher, Schredl and LaBerge, 2003;LaBerge, 1990;Oudiette et al., 2018). Lucid dreaming thus provides a way to establish precise psychophysiological correlations between the contents of consciousness during sleep and physiological measures, as well as enables experimental control over the content of dreams, and therefore provides a potentially highly useful experimental methodology. ...
Lucid dreaming refers to the phenomenon of becoming aware of the fact that one is dreaming during ongoing sleep. Despite having been physiologically validated for decades, the neurobiology of lucid dreaming is still incompletely characterized. Here we review the neuroscientific literature on lucid dreaming, including electroencephalographic, neuroimaging, brain lesion, pharmacological and brain stimulation studies. Electroencephalographic studies of lucid dreaming are mostly underpowered and show mixed results. Neuroimaging data is scant but preliminary results suggest that prefrontal and parietal regions are involved in lucid dreaming. A focus of research is also to develop methods to induce lucid dreams. Combining training in mental set with cholinergic stimulation has shown promising results, while it remains unclear whether electrical brain stimulation could be used to induce lucid dreams. Finally, we discuss strategies to measure lucid dreaming, including best-practice procedures for the sleep laboratory. Lucid dreaming has clinical and scientific applications, and shows emerging potential as a methodology in the cognitive neuroscience of consciousness. Further research with larger sample sizes and refined methodology is needed.
... As illustrated by LaBerge 12 these LRLR eye signals are clearly discernable in the electrooculogram (EOG), enabling precise time-stamping of tasks and events during REM sleep (for replications and extensions see, e.g., refs. 9,13,14 ; for recent implementations see, e.g., refs. 10,15 ). ...
Humans are typically unable to engage in sustained smooth pursuit for imagined objects. However, it is unknown to what extent smooth tracking occurs for visual imagery during REM sleep dreaming. Here we examine smooth pursuit eye movements during tracking of a slow-moving visual target during lucid dreams in REM sleep. Highly similar smooth pursuit tracking was observed during both waking perception and lucid REM sleep dreaming, in contrast to the characteristically saccadic tracking observed during visuomotor imagination. Our findings suggest that, in this respect, the visual imagery that occurs during REM sleep is more similar to perception than imagination. The data also show that the neural circuitry of smooth pursuit can be driven by a visual percept in the absence of retinal stimulation and that specific voluntary shifts in the direction of experienced gaze within REM sleep dreams are accompanied by corresponding rotations of the physical eyes.
... Erlacher and Schredl (2008b) suggest that physically executed and dreamed movements share the same neural mechanisms. Recent findings support this assumption: Correspondences between dreamed and physical movements were found for autonomic responses (Erlacher & Schredl, 2008a), neural activation (Dresler et al., 2011;Erlacher, Schredl, & LaBerge, 2003), and temporal aspects (Erlacher, Schädlich, Stumbrys, & Schredl, 2014). Based on these findings, it can be assumed that lucid dream practice in general could lead to performance enhancement. ...
In a lucid dream, the dreamer is aware of the dream state and can deliberately practice motor skills. Two field studies indicated that lucid dream practice can improve waking performance in simple motor tasks. The present pilot study investigated the effect of lucid dream practice in a controlled sleep laboratory setting, using a pre-post design with dart throwing in the evening and morning. The experimental group practiced darts in lucid dreams. Because some participants were distracted during lucid dream practice, the group was divided into lucid dreamers with few (n = 4) and many distractions (n = 5). Change of performance was compared to a physical practice group (n = 9) and a control group (n = 9), showing a significant interaction (P = .013, η² = .368). Only the lucid dreamers with few distractions improved (18%) significantly over time (P = .005, d = 3.84). Even though these results have to be considered preliminary, the present study indicates that lucid dream practice can be an effective tool in sports practice if lucid dreamers find ways to minimise distractions during lucid dream practice. Moreover, the study emphasises the necessity to investigate lucid dream practice experiences on a qualitative level.
... For philosophers and researchers -mainly in the fields of psychology and sports sciences -lucid dreaming is a REM sleep phenomenon and a means for further investigating the dreaming mind and consciousness as well as neural simulation of actions constrained by sensory input and muscle atonia. Thus, in research, lucid dreams constitute on the one hand a research subject and, on the other hand, can be used as a means to investigate the dream state by asking lucidly dreaming subjects to perform certain tasks and to communicate from the dream by producing previously arranged eye movements that can be identified objectively in EOG recordings (Erlacher, Schredl, & LaBerge, 2003). While lucid dreaming is becoming more prevalent in research (e.g., Stumbrys, Erlacher, Schädlich, & Schredl, 2012) and philosophy (e.g., Windt & Metzinger, 2007), we also find a rising interest in the subject by the media and by individuals all over the world who, for example, actively use web forums on lucid dreaming. ...
In a lucid dream the dreamer is aware of the dream state and can influence the dream content and events. The goal of this study was to investigate some applications of lucid dreaming. Our survey included 301 lucid dreamers who filled out an online questionnaire. The most frequent application (81.4%) was having fun, followed by changing a bad dream or nightmare into a pleasant one (63.8%), solving problems (29.9%), getting creative ideas or insights (27.6%) and practicing skills (21.3%). Women used lucid dreams significantly more often than men for both work on nightmares and problem solving. Our results show that lucid dreams have a great potential for improving one’s life in different ways. More research is needed to illuminate the possibilities of lucid dreaming, especially in the fields of nightmare treatment and practicing motor skills.
... In the following, two recent sleep laboratory experiments studying motor performance in lucid dreams will be described. Erlacher, Schredl, and LaBerge (2003) studied the physiological responses to dreamed motor activities in a single lucid dreamer. Electroencephalographic (EEG) alpha power over motor areas was recorded while the participant subsequently performed a motor task (hand clenching) and control task (counting) in his lucid dream. ...
Nocturnal dreams can be considered as a kind of simulation of the real world on a higher cognitive level. Within lucid dreams, the dreamer is able to control the ongoing dream content and is free to do what he or she wants. In this pilot study, the possibility of practicing a simple motor task in a lucid dream was studied. Forty participants were assigned to a lucid dream practice group, a physical practice group and a control group. The motor task was to toss 10-cent coins into a cup and hit as many as possible out of 20 tosses. Waking performance was measured in the evening and on the next morning by the participants at home. The 20 volunteers in the lucid dream practice group attempted to carry out the motor task in a lucid dream on a single night. Seven participants succeeded in having a lucid dream and practiced the experimental task. This group of seven showed a significant improvement in performance (from 3.7 to 5.3); the other 13 subjects showed no improvement (from 3.4 to 2.9). Comparing all four groups, the physical practice group demonstrated the highest enhancement in performance followed by the successful lucid dream practice group. Both groups had statistically significant higher improvements in contrast to the nondreaming group and the control group. Even though the experimental design is not able to explain if specific effects (motor learning) or unspecific effects (motivation) caused the improvement, the results of this study showed that rehearsing in a lucid dream enhances subsequent performance in wakefulness. To clarify the factors which increased performance after lucid dream practice and to control for confounding factors, it is suggested that sleep laboratory studies should be conducted in the future. The possibilities of lucid dream practice for professional sports will be discussed.
... Este tipo de sueño se puede dar de forma espontánea o bien ser inducido por determinadas prácticas y ejercicios, y en él, el sujeto experimenta diferentes grados de control de la ensoñación. Para averiguar más acerca de las capacidades de aprendizaje deportivo mediante los sueños MOR es de especial relevancia el paradigma de los sueños lúcidos, debido a que las personas que sueñan lúcidamente son capaces de llevar a cabo tareas motoras pre-programadas durante sus sueños, además de marcar el principio y el final de la tarea con las señales del ojo que puede medirse objetivamente por electro-oculograma de grabación (Erlacher, Schredl y LaBerge, 2003). Igualmente, se ha documentado que el entrenamiento en movimientos complejos durante los sueños lúcidos aumenta el rendimiento en vigilia, por lo que se le podría entender como un método de entrenamiento mental, similar en sus características intrínsecas a la visualización (Tholey, 1983). ...
En este estudio se plantea la relación conceptual entre la actividad onírica nocturna de los deportistas y diversas variables psicológicas. Se analizan en primer lugar los marcos teóricos que la justifica; las características de los diversos sistemas de recogida y análisis de los sueños; y los datos existentes en la literatura y en la práctica profesional de los autores acerca de la relación entre sueños y rendimiento o práctica deportiva. Por último, se concluye acerca de las posibles formas de aplicación del estudio y análisis de la actividad onírica del deportista en las intervenciones profesionales en el contexto psicológico deportivo.
... In order to mark events or actions in a lucid dream, lucid dreamers can produce a specific pattern of eye movements (e.g., left-right-left-right) that can be objectively identified on an electrooculogram (EOG) recording (cf. Erlacher et al., 2003). Lucid dreams are especially useful for studying time intervals in the dream state because the beginning and end of a certain action can be marked with eye signals while the sleep is recorded using standard polysomnography. ...
The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.
... This suggests that certain kinds of behavioral reports are possible even during the dream state. Note, however, that in order to rule out false positives, retrospective confirmation is required (Erlacher et al., 2003;Dresler et al., 2011Dresler et al., , 2012. ...
Are dreams subjective experiences during sleep? Is it like something to dream, or is it only like something to remember dreams after awakening? Specifically, can dream reports be trusted to reveal what it is like to dream, and should they count as evidence for saying that dreams are conscious experiences at all? The goal of this article is to investigate the relationship between dreaming, dream reporting and subjective experience during sleep. I discuss different variants of philosophical skepticism about dream reporting and argue that they all fail. Consequently, skeptical doubts about the trustworthiness of dream reports are misguided, and for systematic reasons. I suggest an alternative, anti-skeptical account of the trustworthiness of dream reports. On this view, dream reports, when gathered under ideal reporting conditions and according to the principle of temporal proximity, are trustworthy (or transparent) with respect to conscious experience during sleep. The transparency assumption has the status of a methodologically necessary default assumption and is theoretically justified because it provides the best explanation of dream reporting. At the same time, it inherits important insights from the discussed variants of skepticism about dream reporting, suggesting that the careful consideration of these skeptical arguments ultimately leads to a positive account of why and under which conditions dream reports can and should be trusted. In this way, moderate distrust can be fruitfully combined with anti-skepticism about dream reporting. Several perspectives for future dream research and for the comparative study of dreaming and waking experience are suggested.
... She also points out that lucid dreams are interesting when used to study the body-mind relationship. A recent study (Erlacher, Schredl, & LaBerge, 2003), for example, demonstrated a relationship between activation of the motor brain area and hand clenching carried out within a lucid dream. One chapter, "Creative Chaos," focuses on dreams and creativity (e.g., that Paul McCartney dreamed the melody of "Yesterday"). ...
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) 2012 APA, all rights reserved)
... An experimental approach to this topic could be the technique of lucid dreaming, since it is possible to carry out assigned tasks during the dream (e.g., LaBerge & Rheingold 1990). For a simple motor activity (hand clenching), Erlacher et al. (2003) were able to demonstrate that the related area of the motor cortex was active during the lucid dream (EEG measure). This approach makes sense in the light of the extensive literature on the effect of mental training on performance (e.g., Driskell et al. 1994). ...
In this commentary the “incredibly robust” evidence for the relationship between sleep and procedural memory is questioned; inconsistencies in the existing data are pointed out. In addition, some suggestions about extending research are made, for example, studying REM sleep augmentation or memory consolidation in patients with sleep disorders. Last, the possibility of a relationship between dreaming and memory processes is discussed.
... An experimental approach to this topic could be the technique of lucid dreaming, since it is possible to carry out assigned tasks during the dream (e.g., LaBerge & Rheingold 1990). For a simple motor activity (hand clenching), Erlacher et al. (2003) were able to demonstrate that the related area of the motor cortex was active during the lucid dream (EEG measure). This approach makes sense in the light of the extensive literature on the effect of mental training on performance (e.g., Driskell et al. 1994). ...
We address the notion of integration of new memory representations and the potential dependence of this phenomenon on sleep, in light of recent findings on the lexicalization of spoken words. A distinction is introduced between measures tapping directly into the strength of the newly acquired knowledge and indirect measures assessing the influence of this knowledge on spoken word identification.
... In order to mark events or actions in a lucid dream, lucid dreamers can produce a specific pattern of eye movements (e.g., left-right-left-right) that can be objectively identified on an electrooculogram (EOG) recording (cf. Erlacher et al., 2003). Lucid dreams are especially useful for studying time intervals in the dream state because the beginning and end of a certain action can be marked with eye signals while the sleep is recorded using standard polysomnography. ...
... The analysis of the EEG alpha power showed higher activation of the left hemisphere during counting and higher activation of the right hemisphere during singing, a pattern one would expect also for wakefulness. Erlacher et al. (2003) instructed a single participant to carry out hand clenching either with the right or the left hand or -as a control condition -counting. Those events had to be marked by eye movements allowing the analysis of the EEG alpha power over the motor cortex (C3, CZ and C4) for the left or right hand movements. ...
This chapter addresses the question as to how dream consciousness is related to the physiology of the sleeping body. By reviewing
studies conducted in the field of dream and lucid dream research on REM sleep it can be shown that correlations between dreamed
and actual actions can be found for central nervous activity, autonomic responses and time aspects. In future research, methodological
problems have to be considered and fMRI studies will make it possible to study the relationship between brain activation and
dream content in a detailed way. Studying the body–mind interaction in sleep seems a promising way to understanding dream
consciousness in particular and consciousness in general.
... In the present study, we employed the skill of lucid dreaming to overcome some of these obstacles. In line with the conception that sleep atonia is generated at the brainstem level [4] and confirming earlier EEG studies [20], fMRI BOLD responses were observed bilaterally in the same sensorimotor cortical regions for lucid dreaming and wakefulness. However, during dreaming, activation was much more localized in small clusters representing either generally weaker activation or focal activation of hand areas only, with signal fluctuations only in the order of 50% as compared to the actually executed task during wakefulness. ...
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.
... A wonderful tool which might be available in the future is the fMRI technique applied during REM sleep in order to 'read' the dream without disturbing the sleeper (Dresler, et al., 2008). Simple actions like hand clenching can be detected in the EEG (Erlacher, Schredl, & LaBerge, 2003) or the fMRI scans (Dresler, et al., 2008) of the sleeping person while performing the movements within a lucid dream. Another area that should be pursued in the future is the relationship between REM sleep associated consolidation of emotional memories (Wagner, Gais, & Born, 2001) and dreaming because during REM sleep the amygdala has been found to be very active (Maquet, et al., 1996). ...
A considerable amount of studies have shown that sleep facilitates memory consolidation. For procedural memory, some findings support the association with REM sleep but the relationship between memory consolidation and dreaming has been scarcely studied. The present study did not find an effect of direct incorporations of the mirror tracing task into the dream on over-night improvement. On the other hand, bizarre, long, and intense dreams were associated with poorer performance regarding speed but also with decreased amount of errors. Whether this can be explained by altered sleep physiology or negative effects of dreams on mood and performance can not yet been answered. Future research should study more complex and demanding procedural memory tasks and the relationship between dreaming and sleep-dependent consolidation of emotional memories.
... The ability to recall specific information in lucid dreams raises the question as to whether it is possible to improve waking memory by rehearsal in the dream. For procedural memory (e.g., motor skill learning) pilot studies by Erlach- er, Schredl and LaBerge (2003) and Erlacher and Schredl (2008a) showed a relationship between lucid dreamed ac- tion to actual motor activity (e.g., heart rate) and this leads one to the hypothesis that the learning of motor skills in the simulated environment of dreams is very likely to improve waking performance. For declarative memory thus far no studies have been conducted. ...
The study of lucid dreams is a very sophisticated method to explore the ongoing dream from a first person perspective. The present study explores the ability of lucid dreamers to recall previously learned words in their dreams. For this field study 12 lucid dreamers finished the experimental protocol in a home setting. The results indicate that lucid dreamers are able to recall about 5 out of 7 previously memorised words in their dreams. The recall rate showed a high variation from none to all words. Taking into account that four of the participants couldnt finish the task within the dream the recall rate in the lucid dream seems to be rather high. To control for confounding factors it is suggested to conduct in the future sleep laboratory studies. It also will be promising to study the impact of a lucid dream rehearsal in order to find out if this might be a new method for active learning during the night.
... A pattern one would expect also for wakefulness. In a study by Erlacher, Schredl and LaBerge (2003) a single participant was instructed to carry out hand clenching either with the right or the left hand or -as a control condition -counting. Those events had to be marked by eye movements allowing to analyse the EEG alpha power over the motor cortex (C3, Cz and C4) for the left or right hand movements. ...
This paper addresses the correlation of dreamed and actual actions. This issue is related to the theory of neural simulation of action. The simulation theory postulates that, in general, covert actions are actual actions relying on the same brain regions, except for the fact that they are not executed. By reviewing studies conducted in the field of dream and lucid dream research on REM sleep it will be shown that correlations between dreamed and actual actions can be found for central nervous activity, autonomic responses and time aspects. Recent findings from research on lucid dreaming and motor learning further support the notion that actions in dreams are represented on higher cognitive levels - equivalent to actual movements - and therefore share, to some extent, the same central structures. The reviewed findings will be discussed and future directions will be given.
... Der Kritik der ersten Gruppe kann man nur die inzwischen zahlreichen, unabhängigen Resultate der experimentellen luziden Traumforschung entgegnen (z. B. Dane, 1984;Erlacher, Schredl & LaBerge, 2003;Fenwick et al., 1984;LaBerge, 2000). Zudem scheint ihre Kritik wissenschaftlich nicht sehr fruchtbar, da sie neuen Phänomenen mitübertriebener Skepsis begegnen und trotz einer vielversprechenden Befundlage die Phänomene aus dem Wissenschaftsbereich verbannen. ...
In der vorliegenden Arbeit wird untersucht, inwiefern motorische Lernprozesse durch ein Training innerhalb luzider Träume angeregt werden können. Luzide Träume sind Träume, in denen sich der Träumende seines Zustands bewusst ist und damit Einfluss auf das Traumgeschehen nehmen kann. Das luzide Träumen ist grundsätzlich ein Phänomen des Schlafs, d.h., dass das Training im luziden Traum während des Schlafs stattfindet und somit den kognitiven Strategien im sportlichen Training zugewiesen werden kann. Innerhalb der Arbeit werden Parallelen zwischen dem Training im luziden Traum und dem mentalen Training bzw. der Bewegungsvorstellung herausgearbeitet. Die Theorie der neuronalen Simulation bietet aufgrund zahlreicher empirischer Befunde eine Grundlage, um die Äquivalenz zwischen tatsächlichen und vorgestellten Bewegungen zu beschreiben. Weiterhin werden die für das Verständnis notwendigen Grundlagen des luziden Träumens geliefert (Definition, Häufigkeit, Einflussfaktoren, physiologische Grundlagen, etc.) und Bezüge zwischen der Schlafforschung bzw. Traumforschung und der Sportwissenschaft dargestellt. In einer Reihe von Studien werden grundlagenbezogene, effektorientierte sowie anwendungsbezogene Implikationen des Trainings im luziden Traum untersucht. In den grundlagenbezogenen Studien wird gezeigt, dass Zusammenhänge zwischen zentralnervösen, peripher-physiologischen (z.B. Herzrate) sowie zeitlichen Parametern und Aktivitäten im luziden Traum bestehen. In den effektorientierten Studien wird nachgewiesen, dass das gezielte Üben einer motorischen Fertigkeit im luziden Traum möglich ist. Darüber hinaus bieten die Studien erste Hinweise dafür, dass das Training im luziden Traum zu motorischen Lerneffekten führt. In den anwendungsbezogenen Studien wird gezeigt, dass das luzide Träumen bereits von Sporttreibenden für die Leistungsverbesserung eingesetzt wird. Dies wird anhand von Einzelfällen und zwei Befragungen im Feld verdeutlicht. Zusammenfassend eröffnen die Ergebnisse der vorliegenden Arbeit verschiedene Möglichkeiten für die Sportpraxis als auch für die Sporttheorie und erweisen sich als ein fruchtbares Gebiet für die Sportwissenschaft. In the present doctoral thesis the possibility of motor learning in lucid dreams is examined. The term lucid dream designates a dream in which the dreamer is while dreaming aware that she/he is dreaming. Lucid dreaming is a phenomena of sleep and therefore, practice in lucid dreams happens during sleep. Within this doctoral thesis parallels between practice in lucid dreams and mental practice respectively mental imagery will be presented. The theory of neural simulation offers on the basis of various empirical findings a framework for a central nervous equivalence between actual and mental simulated actions. Furthermore general information about lucid dreaming (definition, prevalence, psychological factors, etc.) and relations between sleep research respectively dream research and sport science will be given. In a series of experiments different aspects about practice in lucid dreams were examined. The sleep laboratory studies focus on the equivalence between dreamed and actual executed motor actions: measuring central nervous activity, monitoring autonomic response and using mental chronometry. In the experimental studies it was shown that it is possible to practice different motor tasks in lucid dreams. Furthermore, preliminary findings suggest that the practice in lucid dreams enhances performance also during actual execution. The questionnaire studies showed that practice in lucid dreams is known and used in sport practice among amateur and professional athletes. To summarize, the results of the present doctoral theses provide different opportunities for the practical field of sport and sport theory.
Lucid dreams often coincide with having control over dream events in real-time, although the limitations of dream control are not completely understood. The current study probed the ability of lucid dreamers to reinstate waking scene memories while dreaming. After brief exposure to an experimental scene, participants were asked to reinstate the scene while lucid dreaming (i.e., change dream scenery to match real-world scene). Qualitative analysis revealed that successful dream scene reinstatements were overwhelmingly inaccurate with respect to the original experimental scene. Importantly, reinstatement inaccuracies held even when the dreamer was aware of them during the dream, suggesting a dissociation between memory access while dreaming and dream imagery. The ability to change the environment of a dream speaks to the high amount of lucid dream control, yet the inaccuracies speak to a lack of detailed control. Reinstating context during lucid sleep offers an experimental method to investigate sleep, dreams, and memory.
In diesem Kapitel soll das Techniktraining im Klartraum näher erläutert werden. Das Klartraumtraining ist das planmäßig wiederholte Ausführen einer sportlichen Handlung mit dem erlebten „Traum-Körper“ in einem Klartraum, mit dem Ziel Bewegungsläufe einzuüben. Es stellt keine tradierte Trainingsmethode dar, jedoch zeigen anekdotische Berichte, Fragebogenstudien, qualitative Studien und experimentelle Untersuchungen, dass sich durch ein Training im Klartraum Bewegungsabläufe für das Wachleben verbessern lassen. Die Wirkungsweise wird dabei mit der Simulationstheorie erklärt, in der kognitive Bewegungsausführungen als eine Simulation der tatsächlichen Bewegung verstanden werden. Für das Klarträumen lässt sich hierfür auf verschiedenen Ebenen Hinweise finden, die dafürsprechen, dass Bewegungen im Traum eine Simulation darstellen. Die bisherigen Befunde sind somit recht vielversprechend, wodurch sich einige konkrete Empfehlung für die Sportpraxis ableiten lassen
Abstract Humans typically lack awareness that they are dreaming while dreaming. However, at times a remarkable exception occurs and reflective consciousness can be regained while dreaming, referred to as lucid dreaming. While most individuals experience lucid dreams rarely there is substantial variance in lucid dream frequency. The neurobiological basis of lucid dreaming is unknown, but evidence points to involvement of anterior prefrontal cortex (aPFC) and parietal cortex. This study evaluated the neuroanatomical/neurofunctional correlates of frequent lucid dreams and specifically whether functional connectivity of aPFC is associated with frequent lucid dreams. We analyzed structural and functional magnetic resonance imaging from an exceptional sample of fourteen individuals who reported ≥3 lucid dreams/week and a control group matched on age, gender and dream recall that reported ≤1 lucid dream/year. Compared to controls, the frequent lucid dream group showed significantly increased resting-state functional connectivity between left aPFC and bilateral angular gyrus, bilateral middle temporal gyrus and right inferior frontal gyrus, and higher node degree and strength in left aPFC. In contrast, no significant differences in brain structure were observed. Our results suggest that frequent lucid dreaming is associated with increased functional connectivity between aPFC and temporoparietal association areas, regions normally deactivated during sleep.
The body-mind interaction has fascinated scientists for a long time, that is, are the subjective experiences (here: dreaming) related to physiology like brain activity or autonomic activity? If we experience severe fear within a nightmare, is the heart rate increasing? Although, the number of studies in this field is still small, empirical evidence is in favor of an interaction between the body and the mind during sleep.
During dreaming, we experience a wake-like hallucinatory reality, however with restricted reflective abilities: in the face of a bizarre dream environment, we do not realize that we are actually dreaming. In contrast, during the rare phenomenon of lucid dreaming, the dreamer gains insight into the current state of mind while staying asleep. This metacognitive insight often enables the dreamer to control own dream actions and the course of the dream narrative. Lucid dreaming allows for radically new methodological and theoretical approaches and has led to new insights in diverse scientific disciplines beyond classical sleep and dream research, including neuroscience, psychotherapy, philosophy, art, and sports sciences. Here, we review past research and the current knowledge on lucid dreaming. We present insights into the scientific work in a sleep laboratory and describe how lucid dreams can be induced through methodologies from diverse academic backgrounds including psychology, electrical engineering and pharmacology.
In the field of sports there is anecdotal evidence for the incorporation of athletic activity in subsequent dreams. The present study investigated dreams of sport students and psychology students with regard to sport related dream content. The findings support the continuity between frequent involvement of sport activities during the day and active participation in sport or sport themes in dreams. These findings will be discussed in the context of motor learning and REM sleep. In future research, the correlation between different performance levels for different sport activities during wakefulness and dream content should be studied in a more detailed way to generate a clearer understanding of the process of sleep-related learning.
The purpose of the present investigation was to explore the potentials for motor learning in a special state of consciousness – so called lucid dreams (dreams in which the dreamers are aware that they are dreaming): its prevalence among athletes, facilitating methods and effectiveness. The contents of this dissertation are structured in the following way. The first chapter introduces the concept of mental practice in sports, reviews the evidence for its effectiveness and presents main theories explaining its effects. Further, the empirical evidence showing the correspondence between imagined and executed actions is discussed, which supports the theoretical view of a functional equivalence between covert and overt motor actions. The second chapter presents the basics of human sleep and the relation of sleep to memory consolidation, especially in terms of procedural (motor) memory. It also introduces the basics of dreams and dream research. The third chapter presents the phenomenon of lucid dreaming, its incidence and frequency rates, underlying physiology and psychology. The fourth chapter, the core of the present investigation, focuses on the application of lucid dreams in sports and, specifically, in motor learning. Anecdotal accounts and previous research is discussed and the present empirical work is introduced. The first study (Paper 1) surveyed the frequency of lucid dreaming and lucid dream practice in athletes. In the second study (Paper 2), a systematic review was conducted to examine the empirical evidence for all different methods for lucid dream induction that have been suggested in the literature. Then a sleep laboratory study followed to test one of the prospective methods suggested in the literature but not yet examined – an induction of lucid dreams via transcranial brain stimulation (Paper 3). Lastly, an online study was carried out in which the effectiveness of motor practice was compared to actual physical practice and mental practice in wakefulness (Paper 4). Finally, the last chapter provides an overall discussion of the findings and directions for future research.
Reviews the book,
The dream experience: A systematic exploration by Milton Kramer (see record
2007-01084-000). This book was written by an exceptional scientist and clinician and is based on 46 years of productive work in the field of dream research and sleep medicine. Milton Kramer presents some preliminary data about two patterns that describe changes in dream content over one night: the progressive-sequential dream pattern and the repetitive-traumatic dream pattern, each illustrated with an example. The first pattern reflects some kind of progression reflecting a successful coping with the problem of the first dream. The second pattern repeats one topic but without introducing successful coping strategies. Milton Kramer's book is a comprehensive overview of dream research over the last 50 years and I recommend it to anyone who is interested in pursuing this field of research. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
In this chapter, we review relevant research and theories on time-based and event-based prospective remembering. We propose and describe two models, one that explains time-based prospective remembering (the attentional-gate model) and one that explains event-based prospective remembering (the recursive-reminding model). We show how these models are able to account for some of the major findings in the literature, as well as to guide future research. A consideration of how the two kinds of processes may interact in some mixed time-based and event-based situations is also included. We conclude by mentioning a few unusual applications in altered states of consciousness. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Following on from the target article, which presented a new model of procedural skill memory development, in this response I will reflect on issues raised by invited commentators and further expound attributes of the model. Discussion will focus on: evidence against sleep-dependent memory processing, definitions of memory stages and memory systems, and relationships between memory enhancement, sleep-stages, dreaming, circadian time, and sleep-disorders.
As a general activation of the mind, mental arousal characterizes the level of consciousness, irrespective of its content.
Recently, a parameter called the brain rate (expressing the mean frequency of brain rhythms) has been introduced. It appears
that the brain rate, which is equal to an EEG spectrum weighted frequency, can serve as a diagnostic indicator of general
mental activation (level of consciousness) and serve in addition to heart rate, blood pressure, and temperature as a standard
indicator of general bodily activation. Empirically, it has been shown that brain rate measurements can be used to discriminate
between the groups of under-arousal and over-arousal disorders, and to assess attention deficit hyperactivity disorder, inner
arousal, and the quality of sleep, as well as to indicate the IQ changes caused by some environmental toxins. Brain rate is
also suitable for revealing the patterns of sensitivity/rigidity in the EEG spectrum, including frequency bands related to
the permeability of corresponding neuronal circuits, based on which individually adapted biofeedback protocols can be specified.
The problem of consciousness is mostly regarded as identical to the mind-body problem. According to Chalmers’ philosophical arguments, the hard problem of consciousness lies in establishing and explaining the link between physical processes and conscious experiences, via psychological processes. A brief history of various theories of consciousness is given and a selection of theories are tested against Zeman’s three fundamental intuitions and Chalmers’ controversial zombie argument. The hard problem
of consciousness is further described using Levine’s notion of an explanatory gap between physical matter and conscious experience, through the first and third persons. Various states, contents, levels and processes of consciousness are summarised, including Damasio and Meyer’s dual perspective for defining consciousness. Tart’s three definitions do not entirely describe altered states of consciousness. While the challenge of finding the core function of human and animal sleep remains unknown when tested
under the null hypothesis, studies on the neural correlates of consciousness during meditation have revealed neuroplasticity effects. The synchrony of gamma brain oscillations reflecting various styles of meditation or attention, also known as the binding problem, may be related to conscious experiences. This binding problem with gamma brain oscillatory synchronization also arises in relation to sensory awareness or perception, affecting the perception of time and hallucinatory experiences in various disorders of consciousness such as severe schizophrenic and déjà vu (in healthy or epileptic) patients. In conjunction with medication treatments, music therapy is often useful in accelerating the healing process in most such disorders of consciousness. It is still unknown how this sensory awareness to music is perceived in medicated patients suffering from disorders of consciousness. More clinically elusive are near death experiences, in which consciousness persists independently of brain function, where there is no scientific basis for such consciousness to exist and no physiological or psychological model that can explain it. Near death experiences can be regarded as a special state of consciousness, which provides further evidence that the consciousness problem may be very close to the mind-body problem that originates in Descartes’ classic theory of dualism and is transformed into Chalmers’ contemporary theory of natural dualism. The final section of this chapter offers an overview of all invited chapters.
Music has been used since ancient times in healing rituals. It has been played for people to induce altered states of consciousness
(ASC), which change the focus of attention, mood, and thoughts about the world and the self. Music and altered states are
connected in various ways concerning context, personal set, socio-ecological setting, and cultural beliefs. Discussion is
ongoing as to whether music itself induces the changes via a “trance mechanism” or whether the setting and rituals connected
to music are responsible for the induction of ASC. The authors conducted an explorative attempt to represent interdependencies
of set and setting, sound and trance through electrophysiological correlation in the topographic spontaneous EEG. They opted
for a sound trance induction with the sound of a body monochord (a bed-like stringed instrument producing a droning sound)
in the context of a group ritual. In comparison with uninfluenced rest, they found individual changes in spontaneous EEG.
Trance reactions to sound were seemingly more determined by the person’s susceptibility to hypnosis as measured by the Phenomenology
of Consciousness Inventory than by sound alone.
„Tapfer hielt er bis zu seinem unglaublichen Ende bei sich, dass die Zeit des Schlafs Verschwendung und folglich Sünde sei,
ihm dereinst im Fegefeuer aufgerechnet werde, denn im Schlaf sei man tot, jedenfalls lebe man nicht wirklich. Nicht von ungefähr
vergliche ein altes Wort Schlaf und Tod mit Brüdern.“ Dieses Zitat aus Robert Schneiders bekanntem Roman Schlafes Bruder macht die verbreitete Geringschätzung deutlich, die dem Schlaf von alters her zuteilwird. Das gilt ganz besonders für die
heutige Leistungs-und Freizeitgesellschaft, in der der Schlaf zwar nicht mehr mit Tod oder Sünde gleichgesetzt, dafür aber
umso mehr als überflüssige bzw. nutzlose Lebenszeit betrachtet wird („Das Leben ist zu kurz, um zu schlafen“). Aus neuropsychologischer
Sicht ist der schlechte Ruf des Schlafs nicht zu rechtfertigen. Schlaf dient nicht nur der körperlichen Regeneration, sondern
auch psychologischen Funktionen, ohne die eine normale Lebensführung auf die Dauer nicht möglich ist..
Falling asleep is a link between two general states of consciousness, wakefulness and sleep. During the complex process of the wake to sleep transition, various electrophysiological, cognitive and behavioural alterations take place, all linked to states of consciousness. Together, these states have been interpreted as the hypnagogic state. It is no longer believed that sleep onset just acts as a buffer between the awake and sleep processes characterised by the gain and loss of sensory functioning, respectively. On the contrary, the sleep onset phenomenon addresses many issues surrounding some of the most common sleep and mental disorders. What is the moment of sleep onset? How can sleep onset be characterised from the brain, heart and respiration activity during sleep in humans? These are some of the questions that have no clear and definite answers. Neural synchrony and its interaction and coupling with cardio-respiratory synchrony is very much related to its role as a mechanism for integrating brain, heart and respiration, which are all responsible for consciousness, in both humans and animals. The phase synchrony between neural, cardio and respiratory activities and environment provides a signature of subjective experiences, linked to various states of consciousness. Technological advances have led to a gradual shift in the approach adopted by the scientific community towards unravelling and understanding this sleep onset phenomenon as an altered state of consciousness. This chapter presents research from the scientific community, explores some new objective indices that can be adopted to measure sleep
onset, and demonstrates how sleep onset can be voluntarily altered and induced using biofeedback technology.
Altered states of consciousness provide valuable insights essential for a better understanding of the phenomenon of consciousness.
Improved understanding of physiological correlates of states with expanded consciousness may allow possible use of biofeedback
as a tool for achieving of those states at will. As a consequence, this approach may facilitate improvement of efficiency,
creativity, and spiritual growth. This chapter presents a survey of relevant physiological correlates and present examples
of two specific techniques: slow yogic breathing and chanting. We hypothesize that stabilization of physiological rhythms,
such as breathing, heart rate variability, or blood pressure variability, creates favorable conditions in which states of
expanded consciousness may arise.
It may eventually be possible to identify completely the temporal sequences of electrical microstates that underlie consciousness.
From these “codons of consciousness” a DNA-like mathematical model of normal sequencing of the “atoms of thought” could be
constructed and matched to subjective experience and behaviour. This would allow the prediction of thought and behaviour from
the building blocks of consciousness. Having an intimate knowledge of the sequencing of units of consciousness may allow abnormal
patterns of behaviour to be identified even in early childhood and appropriate corrective treatments to be developed. The
development of this research may result in treatments for the main pathological problems that trouble all human kind.
Although so-called states of consciousness have been the focus of considerable contemporary multi-disciplinary interest, this
concept is neither well defined nor sufficiently understood. While definitions of “consciousness” usually distinguish it from
its content, definitions of “states of consciousness” typically confuse consciousness and its contents by explicitly stating
that a state of consciousness is the content (i.e., mental episodes) available to conscious awareness. In other words, the term “states of consciousness,”
along with the intimately related term “altered states of consciousness,” rests on a conflation of consciousness and content
whereby consciousness is erroneously categorized in terms of content rendered perceptible, presumably by consciousness “itself.”
This error, which we call the consciousness/content fallacy, may be avoided if one supplants “[altered] states of consciousness”
with a new term, “[altered] pattern of phenomenal properties,” an extrapolation of the term “phenomenal field.”
Sleep and dreaming are overlapping and inseparable phenomena, but they have not often been addressed simultaneously in the
scientific sleep research literature. This chapter describes dream research with a focus on objective dream content analysis
and on neurocognitive theory analysis. Special emphasis is placed on connecting dream content analysis with current and advanced
sleep research methodologies. This chapter presents some of the traditional and current interventions on dreaming during the
periods of REM and NREM sleep, namely the behavioral and physical interventions. A more holistic view is provided through
the description of the relationship of REM–NREM sleep and dreaming neurophysiology with the autonomous nervous system. A survey
of current dream therapy usage is discussed in the light of the holistic approach provided, with the aim of showing pathways
for future applications.
Consciousness can be defined by two components: arousal and awareness. Disorders of consciousness (DOC) are characterized
by a disrupted relationship between these two components. Coma is described by the absence of arousal and, hence, of awareness
whereas the vegetative state is defined by recovery of arousal in the absence of any sign of awareness. In the minimally conscious
state, patients show preserved arousal level and exhibit discernible but fluctuating signs of awareness. The study of DOC
offers unique insights to the neural correlates of consciousness. We here review the challenges posed by the clinical examination
of DOC patients and discuss the contribution of functional neuroimaging and electrophysiological techniques to the bedside
assessment of consciousness. These studies raise important issues not only from a clinical and ethical perspective (i.e. diagnosis,
prognosis and management of DOC patients) but also from a neuroscientific standpoint, as they enrich our current understanding
of the emergence and function of the conscious mind.
KeywordsBrain injury-Coma-Consciousness-Electrophysiology-Functional neuroimaging-Locked-in syndrome-Minimally conscious state-Prognosis-Treatment-Vegetative state
Several large-scale studies showed that women tend to report nightmares more often than men. Despite this robust finding, empirically tested interpretations of these sex differences are lacking. Levin and Nielsen put forward the hypothesis that sex-specific socialization might be one of the risk factors for nightmare occurrence. The present findings of an online survey indicate that expressivity/femininity and instrumentality/masculinity were related to nightmare fre quency and, thus, supported this hypothesis. Since the sex difference in nightmare frequency was not fully explained by these two variables, future studies should investigate other variables--in addition to sex-role orientation--like depressive symptoms, history of sexual and/or physical abuse, ruminative coping styles, and physiological measures of processing emotional stimuli within the brain.
The occurrence of lucid dreaming (dreaming while being conscious that one is dreaming) has been verified for 5 selected subjects who signaled that they knew they were dreaming while continuing to dream during unequivocal REM sleep. The signals consisted of particular dream actions having observable concomitants and were performed in accordance with pre-sleep agreement. The ability of proficient lucid dreamers to signal in this manner makes possible a new approach to dream research--such subjects, while lucid, could carry out diverse dream experiments marking the exact time of particular dream events, allowing derivation of of precise psychophysiological correlations and methodical testing of hypotheses.
A night of sleep has been recorded under the conditions of a sleep laboratory. The subject was a woman of 55 years, well-trained in dream recall. The subject was awakened three times at the end of sleep cycles. EEG was monitored for 7 h with a 16-channel polygraph (REEGA 16, Alvar) connected to two systems of EEG cartography: minicomputers (HP Fourier Analyser 5451 C and HP 1000) and a microinformatic system (Cartovar, Alvar). A second 8-channel polygraph (Mini-huit, Alvar) was used in parallel for polygraphy (EOG, EMG, respiration, actogram, EKG). Based on immediate visual inspection of EEG and polygraphic tracings, 500 EEG recordings of selected epochs (of 6, 30 or 60 s length) have been quantified, submitted on-line to spectral analysis (on Cartovar) and stored on floppy disks for further printing of EEG maps. The 16 EEG channels were placed over the scalp according to the 10/20 system and following Giannitrapani's placement. We have chosen a common average electrode. For each of the 500 EEG epochs, four EEG maps were edited (raw EEG between 0 and 30 Hz, 0 and 7 Hz, 8 and 12 Hz, 13 and 30 Hz). Each of these 2,000 maps has been checked visually in comparison with the polygraphic recordings for visual rejection of artifacts or transitory states. The remaining EEG epochs and EEG maps, scored by 2 independent trained sleep scorers, were classified into stages I, II, III-IV, and REM, apart from control runs of active wakefulness with eyes open (EO) and quiet wakefulness with eyes closed (EC), which were undertaken on mini- and microsystems of EEG analysis.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to study the neural substrate for eye movements during rapid eye movement (REM) sleep, we analyzed the positron emission tomography (18Fluorodeoxyglucose positron emission tomography) scan data obtained from normal subjects. Eye movement data were available on nine subjects studied during nighttime REM sleep and six control subjects studied during waking as they periodically moved their eyes. The number of eye movements during REM sleep was positively correlated with glucose metabolic rate in the areas corresponding to (a) the saccadic eye movement system (frontal eye field and dorsolateral prefrontal cortex, statistically significant only on the right side), (b) the midline attentional system (cingulate and medial frontal cortex, precuneus) and (c) the parietal visual spatial attentional system (bilateral superior parietal lobules, right inferior parietal lobule); and negatively correlated with relative metabolic rate in the left inferior parietal lobule. Positive correlations between waking eye movements and metabolic rate were observed in the same areas except inferior parietal lobule. Our results show that the same cortical areas are involved in eye movements in both REM sleep and wakefulness and suggest that REM sleep eye movements are saccadic scans of targets in the dream scene. Our data also suggest right hemispheric specialization in saccadic eye movement control and reciprocal inhibition in the contralateral homologous area during higher cortical functioning.
1 I. INTRODUCTION 2 A. An Integrative Strategy 2 B. A State Space Model of the Brain-Mind 3 C. Caveat Lector 4 II. THE PHENOMENOLOGY AND PSYCHOPHYSIOLOGY OF WAKING, SLEEPING AND DREAMING 5 DREAMING and the BRAIN: Toward a Cognitive Neuroscience of Conscious States http://home.earthlink.net/~sleeplab/bbs/BBS.html (1 of 222) [1/6/2000 2:48:02 PM] A. Early findings of distinct differences between REM and NREM mentation 6 B. Overview of the NREM-REM Sleep Mentation Controversy 12 1. REM Sleep Dreaming is not Qualitatively Unique 13 2. The Relationship Between Dream Features and Dream Report Length 17 C. Methodological Considerations in the Study of Dreaming 21 1. The Reduction of Psychological States to Narrative Reports 21 2. The Sleep Laboratory Environment 26 3. The Question of "Similarity" and "Difference" 29 4. The Source and Fate of Dream Memory 33 5. Type I vs. Type II Statistical Analyses 39 6. The Need for New Approaches 40 III. THE COGNITIVE NEUROSCIENCE OF WAKING, SLEEPING AN...
Although we are usually unaware of the fact that we are dreaming while we are dreaming, at times a remarkable exception occurs, and our consciousness becomes lucid enough for us to realize that we are dreaming. Lucid dreamers report being able to freely remember the circumstances of waking life, to think clearly, and to act deliberately upon reflection, all the while experiencing a dream world that seems vividly real (Green, 1968; LaBerge, 1985a). This is all in contrast to the usual characterization of dreams as typically lacking any reflective awareness or true volition (Rechtschaffen, 1978).
Lucid dreaming provides a test case for theories of dreaming. For example, whether or not “loss of self-reflective awareness” is characteristic of dreaming, it is not necessary to dreaming. The fact that lucid dreamers can remember to perform predetermined actions and signal to the laboratory allows them to mark the exact time of particular dream events, allowing experiments to establish precise correlations between physiology and subjective reports, and enabling the methodical testing of hypotheses.
[Hobson et al.; Solms]
The central question facing sleep and dream science today seems to be: What is the physiological basis of the subset of NREM dreams that are qualitatively indistinguishable from REM dreams (“apex dreams”)? Two competing answers have emerged: (1) all apex dreams are generated by REM sleep control mechanisms, albeit sometimes covertly; and (2) all such dreams are generated by forebrain mechanisms, independently of classical pontine sleep-cycle control mechanisms. The principal objection to the first answer is that it lacks evidential support. The principal objection to the second answer (which is articulated in my target article) is that it takes inadequate account of interactions that surely exist between the putative forebrain mechanisms and the well established brainstem mechanisms of conscious state control. My main response to this objection (elaborated below) is that it conflates nonspecific brainstem modulation – which supports consciousness in general – with a specific pontine mechanism that is supposed to generate apex dreaming in particular. The latter mechanism is in fact neither necessary nor sufficient for apex dreaming. The putative forebrain mechanisms, by contrast, are necessary for apex dreaming (although they are nor sufficient, in the limited sense that all conscious states of the forebrain are modulated by the brainstem).
Typescript (photocopy). Thesis (Ph. D.)--Stanford University, 1980. Includes bibliographical references (leaves 121-129).
Ten adult subjects, selected for good dream recall and ability to produce spontaneously fine limb movements in the laboratory, reported their last dream experience after awakenings from REM sleep during various limb movement and no movement conditions. The reports were rated for amount and girdle location of dreamed actions by judges blind to the awakening condition. There was a significant correlation between the number of girdles moving before awakening and the amount of dreamed action. Also, when dreams from single girdle movement awakening conditions were examined, the girdle active before awakening was dreamed as moving to a significant degree.
Oscillations in the alpha and beta bands can display either an event-related blocking response or an event-related amplitude enhancement. The former is named event-related desynchronization (ERD) and the latter event-related synchronization (ERS). Examples of ERS are localized alpha enhancements in the awake state as well as sigma spindles in sleep and alpha or beta bursts in the comatose state. It was found that alpha band activity can be enhanced over the visual region during a motor task, or during a visual task over the sensorimotor region. This means ERD and ERS can be observed at nearly the same time; both form a spatiotemporal pattern, in which the localization of ERD characterizes cortical areas involved in task-relevant processing, and ERS marks cortical areas at rest or in an idling state.
The influence of planning of self-paced voluntary finger movements on alpha band components was studied in 6 volunteers. Brain potentials from 29 electrodes, referred to the right ear, were recorded 4 sec before and 2 sec after movement onset. These data were transformed to obtain the laplacian operator, which was done by computing the local average reference. The event-related desynchronization (ERD) of upper alpha components was then calculated in each record at intervals of 250 msec and topographically displayed in the form of serial ERD maps. A first significant ERD (P less than 0.01, sign test) was found 1.75 sec +/- 0.61 before the movement, most prominent over the contralateral sensorimotor area and over midfrontal areas (the latter can probably be interpreted as an activation of the supplementary motor area). From these data we can conclude that the side of movement is predetermined more than 1 sec before movement onset.
Four men, aged 67-72 years, had 4-month to 6-year histories of injuring themselves or their spouses with aggressive behaviors during sleep, often during attempted dream enactment. A 60-year-old woman had disruptive though nonviolent sleep and dream behaviors. Polysomnography did not detect seizures but did document REM sleep pathology with variable loss of chin atonia, extraordinarily increased limb-twitch activity, and increased REM ocular activity and density. A broad range of REM sleep behaviors was recorded on videotape, including stereotypical hand motions, reaching and searching gestures, punches, kicks, and verified dream movements. Stage 3-4 slow wave sleep was elevated for age in all patients. NREM sleep was devoid of harmful behaviors, although three men had periodic myoclonus. There was no associated psychiatric disorder, whereas serious neurologic disorder was closely associated in four cases: olivo-ponto-cerebellar degeneration, Guillain-Barré syndrome, subarachnoid hemorrhage, and an atypical dementia. Two patients had immediate and lasting sleep behavioral suppression induced by clonazepam, and another patient had the same response with desipramine. All instances of drug discontinuation prompted immediate relapse. In four cases there was associated dream hyperactivity, which resolved with behavioral control. These REM sleep neurobehavioral disorders constitute another category of parasomnia, replicate findings from 21 years ago in cats receiving pontine tegmental lesions, and offer additional perspectives on human behavior, neurophysiology, pharmacology, and dream phenomenology.
1. Previous studies in man have revealed a coupling between the regional cerebral blood flow (rCBF) and the regional cerebral metabolic rate for oxygen. In normal man, increases in the regional cerebral metabolic rate for oxygen leads to proportional increases in the rCBF(34). We have measured the rCBF as an expression of the level of cortical activity simultaneously from 254 cortical regions in 28 patients with no major neurological defects, during rest and during planning and execution of a few types of learned voluntary movements with the hand. 2. We found that the rCBF increases exclusively in the supplementary motor area while subjects were programming a sequence of fast isolated movements of individual fingers, without actually executing it. 3. During execution of the same motor sequence, there were equivalent increases of the rCBF in both supplementary motor areas, but only in the contralateral primary motor area. In addition, there were more modest rCBF increases in the contralateral sensory hand area, the convexity part of the premotor area, and bilaterally in the inferior frontal region. 4. Repetitive fast flexions of the same finger or a sustained isometric muscular contraction raise the blood flow in the contralateral primary motor and sensory hand area. 5. A pure somatosensory discrimination of the shapes of objects, without any concomitant voluntary movements, also leaves the supplementary motor areas silent. 6. We conclude that the primary motor area and the part of the motor system it projects to by itself can control ongoing simple ballistic movements with the self-same body part. A sequence of different isolated finger movements requires programming in the supplementary motor areas. We suggest that the supplementary motor areas are programming areas for motor subroutines and that these areas form a queue of time-ordered motor commands before voluntary movement are executed by way of the primary motor area.
The spatiotemporal patterns of Rolandic mu and beta rhythms were studied during motor imagery with a dense array of EEG electrodes. The subjects were instructed to imagine movements of either the right or the left hand, corresponding to visual stimuli on a computer screen. It was found that unilateral motor imagery results in a short-lasting and localized EEG change over the primary sensorimotor area. The Rolandic rhythms displayed an event-related desynchronization (ERD) only over the contralateral hemisphere. In two of the three investigated subjects, an enhanced Rolandic rhythm was found over the ipsilateral side. The pattern of EEG desynchronization related to imagination of a movement was similar to the pattern during planning of a voluntary movement.
The work of Kleitman and his students1-4 has demonstrated conclusively that a low-voltage, fast-activity electroencephalographic (EEG) pattern during sleep is typically associated with dreaming. By continuous monitoring of brain waves during sleep, it is now possible to localize the dream as it occurs. The discovery of the association of a specific EEG pattern with dreaming was antedated by the observation that rapid, conjugate eye movements during sleep are associated with visual dreams.1-3,5 Not all dreams are visual, however, and dreams without rapid eye movements (REM’s) have been observed to be nonvisual in nature. Indeed, the amount of reported physical activity by the dreamer has been found by Dement and Wolpert5 to be related to the amount of eye movement observed electrically, the EEG pattern being constant regardless of the amount of activity in the dream. In addition, the spatial direction of the
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