Daniel Erlacher's research while affiliated with HES-SO Valais-Wallis and other places

Publications (100)

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Zusammenfassung Hintergrund Schlaf spielt auch für SportlerInnen eine wichtige Rolle, vor allem vor Wettkämpfen. Ziel der Arbeit In einer Stichprobe von NachwuchsathletInnen soll erfasst werden, ob ein gestörter Schlaf vorliegt und welche Ursachen und Auswirkungen ein gestörter Schlaf vor Wettkämpfen aus subjektiver Sicht hat. Material und Metho...
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In a previous questionnaire study with German professional athletes, we showed that the prevalence of lucid dreaming in athletes is 57% and that about 5% of athletes use their lucid dreams to practice sport skills while asleep. The present study applied a Japanese translation of the same questionnaire to a Japanese sample of college athletes to exp...
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Lucid dreaming offers the chance to investigate dreams from within a dream and by real-time dialogue between experimenters and dreamers during REM sleep. This state of consciousness opens a new experimental venue for dream research. However, laboratory study in this field is limited due to the rarity of lucid dreamers. In a previous study, we were...
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Anecdotal evidence that lucid dreaming might contribute to mental and physical health has been widely reported in the literature. Empirical research, though, is scarce. A brief questionnaire eliciting self-perceived benefits of lucid dreaming on mental and physical health had been completed by 386 participants who had lucid dream experiences. About...
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Lucid dreaming, the fact that one knows that they are dreaming while dreaming, provides a unique paradigm for the study of the distinctive psychophysiological state of dreaming and consciousness. Unfortunately, frequent lucid dreamers are rare and techniques should be established to reliably induce lucid dreams. Here the induction of lucid dreams w...
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The reliable induction of lucid dreams is a challenge in lucid dream research. In a previous study by our research group we were able to induce in about 50% of the participants a lucid dream in a single sleep laboratory night by combining a wake-up-back-to-bed sleep protocol and a mnemonic technique. In the present study, we extended our previous p...
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It is widely accepted that sleep better facilitates the consolidation of motor memories than does a corresponding wake interval (King et al., 2017). However, no in-depth analysis of the various motor tasks and their relative sleep gain has been conducted so far. Therefore, the present meta-analysis considered 48 studies with a total of 53 sleep (n...
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Lucid dreaming offers many opportunities to study consciousness processes. However, laboratory research in this area is limited because frequent lucid dreamers are rare. Several studies demonstrated that different methods of induction could increase the number of lucid dreams. In four field studies, a combination of a wake-up-back-to-bed (WBTB) sle...
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In addition to a large variety of somatic symptoms, fever also affects cognition, sleep, and mood. In an online survey with 164 participants, 100 fever dream reports were submitted. Fever dreams were more bizarre and more negatively toned and included more references to health and temperature perception compared to “normal” most recent dreams – fin...
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In diesem Kapitel soll der Prozess der Gedächtniskonsolidierung im Schlaf für motorische Fertigkeiten dargelegt werden. Grundsätzlich werden Gedächtnisinhalte explizit (bewusst und willentlich) oder implizit (unbewusst) erinnert und dementsprechend zwischen deklarativem und non-deklarativem Gedächtnis unterschieden. Die unterschiedlichen Gedächtnis...
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In diesem Kapitel soll die Klartraumforschung skizziert werden. Der Klartraum ist ein Traum, in dem sich die Person während des Traums bewusst wird, dass er oder sie gerade träumt. Dadurch ist es beispielsweise möglich, dass Traumgeschehen zu steuern. Da sich diese Möglichkeit nicht immer ergibt, ist es zunächst wichtig den Begriff Klartraum gut zu...
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In diesem Kapitel sollen die Grundlagen der Schlafforschung beschrieben werden. Dabei steht vor allem die Frage der Schlafmessung im Vordergrund. Der goldene Standard der Schlafmedizin ist dabei die so genannte Polysomnographie. Da diese sehr aufwendig ist, werden auch alternative Erfassungsmethoden wie die Aktigraphie oder subjektive Schlafmessung...
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In diesem Kapitel soll das Traumerleben von Sportlerinnen und Sportlern näher betrachtet werden. Für sportliche Aktivität zeigt sich eine Kontinuität zwischen Wacherleben und Trauminhalten, wer intensiv Sport treibt träumt auch häufig davon. Die Trauminhalte können sich negativ oder positiv auf das Wachleben auswirken. Albträume beispielsweise über...
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In diesem Kapitel sollen die unterschiedlichen Facetten von Wahrnehmung und Handlung im Rahmen von parasomnischen Störungen betrachtet werden. Die verschiedenen Störungen zeichnen sich durch eine Dissoziation zwischen Wach und Schlaf/Traum wobei zwei extreme Phänomene existieren: Schlafwandeln und Klarträumen. Im ersten Fall finden Handlungen in de...
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In diesem Kapitel soll die Auswirkung von mangelndem Schlaf auf die sportliche Leistung dargestellt werden. In der Schlafforschung wird zwischen totalem, partiellem und selektivem Schlafentzug unterschieden. Bei Ratten führt unter experimentellen Bedingungen ein Schlafentzug von zwei bis drei Wochen zum Tod. Beim Menschen sind aus ethischen Gründen...
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In diesem Kapitel soll das Schlafverhalten von Athletinnen und Athleten in den verschiedenen Sportarten näher betrachtet werden. Das Schlafverhalten wurde in der Sportpraxis überwiegend durch die Aktigraphie erhoben. Die methodischen Besonderheiten der Aktigraphie (z. B. Unter-/Überschätzung von Wachzeiten) werden deshalb gesondert diskutiert. Ansc...
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In diesem Kapitel sollen verschiedene Perspektiven der Sportwissenschaft skizziert werden. Die Sportwissenschaft versteht sich als eine Querschnittsdisziplin, die je nach Betrachtung der Sportpraxis, für ein und dieselbe Situation des Sports unterschiedliche Antworten liefert. Mit der Trainingswissenschaft, Sportmotorik, Sportpsychologie, Sportmedi...
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In diesem Kapitel sollen die Grundlagen der experimentell-psychologischen Traumforschung beschrieben werden. Zunächst wird eine Definition für den Forschungsgegenstand Traum geliefert. Die Traumerinnerung spielt dabei eine wesentliche Rolle, wobei noch ungeklärt ist, warum sich Menschen gut oder schlecht an ihre Träume erinnern. Anschließend werden...
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In diesem Kapitel sollen ganz allgemein Flugreisen im Sport und der Jetlag im speziellen betrachtet werden. Flugreisen sind für viele Athletinnen und Athleten im Hochleistungssport ein unvermeidbarer Stress, egal ob es sich um regelmäßige Kurzstrecken oder gelegentliche Fernreisen handelt. Dabei muss zwischen der Reisemüdigkeit und dem Jetlag unter...
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In diesem Kapitel soll der Schlaf vor, während und nach sportlichen Wettkämpfen skizziert werden. Sportliche Wettkämpfe können in zweierlei Hinsicht Stress bedeuten: Den erwarteten physischen Stress durch die körperliche Anstrengung und psychischen Stress, der mit Angst, Unsicherheit etc. zu tun hat. Fragebogenstudien zeigen, dass vor, während und...
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In diesem Kapitel soll die schlafförderliche Wirkung von körperlicher Aktivität auf die Qualität des Schlafes erläutert werden. Dabei wird ein Überblick über die Effekte einmaliger oder regelmäßiger physischer Aktivität auf den Schlaf – von Gesunden oder auch von schlafgestörten Personen – gegeben. Die bisherigen Studien mit Personen, die an insomn...
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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, Frage...
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A B S T R AC T In a lucid dream the dreamer is aware of the dream state and can carry out actions deliberately. Lucid dream practice (LDP) is the rehearsal of movements during lucid dreams and constitutes a specific form of mental practice (MP). Previous studies demonstrated that LDP can enhance physical performance. To gain deeper insight into LDP...
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In a lucid dream, the dreamer knows that he or she is dreaming and can thus deliberately carry out actions. The original goal of this study was to investigate musical practice in lucid dreams and its possible effects as well as the quality of the experiences. A total of 5 musicians were interviewed about their lucid dreams in which they had played...
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The body of research that reports the relevance of sleep in high-performance sports is growing steadily. While the identification of sleep cycles and diagnosis of sleep disorders is limited to lab-based assessment via polysomnography, the development of activity-based devices estimating sleep patterns provides greater insight into the sleep behavio...
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The relationship between recovery and fatigue and its impact on performance has attracted the interest of sports science for many years. An adequate balance between stress (training and competition load, other life demands) and recovery is essential for athletes to achieve continuous high-level performance. Research has focused on the examination o...
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In lucid dreams, the dreamer is aware that one is dreaming; however, this does not necessary imply that the dreamer has complete control over the ongoing dream narrative. The present study explored the extent to which the lucid dreamers are able to control their dreams, as well as underlying factors. An online survey was completed by 528 respondent...
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Lucid dreamers may encounter not only friendly but also threatening dream figures in their lucid dreams. The present study of German-speaking lucid dreamers explored the frequency of threatening dream figures in lucid dreams and how lucid dreamers responded to them. An online questionnaire was completed by 528 respondents, of whom 386 had lucid dre...
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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 wi...
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Objective/background: The aim of this study was to examine the effects of competitions on subjective sleep quality. Previous studies have been inconclusive and lack differentiated and standardized measurements of subjective sleep quality. Furthermore the temporal relation between precompetitive anxiety and sleep quality was investigated. Anxiety a...
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In lucid dreams the dreamers are aware that they are dreaming and can use this state for a variety of different purposes. In an online survey, 528 respondents, of whom 386 were lucid dreamers, were asked how often have they used different applications of lucid dreams lately and how did this influence their mood upon awakening. According to the repo...
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Background/aim: There is increasing popularity for athletes to use heart rate variability (HRV) to tailor training. A time-efficient method is HRV assessment during deep sleep. The aim was to validate the selection of deep sleep segments identified by RR-intervals with simultaneous electroencephalography (EEG) recordings and to compare HRV paramet...
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Dreaming plays a role in all major world religions, so it was expected that dream recall frequency was positively related to a measure of spirituality (“Transpersonal Trust”). The findings of the online survey (N = 528) indicate that there is a relationship between spirituality and dream recall, possibly mediated by mindfulness skills. Two factors...
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Motor practice in lucid dreams is a form of mental rehearsal where the dreamer can consciously rehearse motor skills in the dream state while being physically asleep. A previous pilot study showed that practice in lucid dreams can improve subsequent performance. This study aimed to replicate those findings with a different task (finger-tapping) and...
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The present study explored the relationship between lucidity in dreams (awareness of dreams while dreaming) and mindfulness during wakefulness, also considering meditation as a possible moderating variable. An online survey was completed by 528 respondents, of whom 386 (73.1%) had lucid dream experiences. The reported frequency of lucid dreams was...
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Two exploratory online experiments were carried out to investigate the interaction between dream characters and the dream ego in lucid dreams. Lucid dreamers were recruited via an Internet page (http://klartraum.de). In Experiment 1, 15 participants (26.5 ± 10.2 years; 4 female, 11 male) provided 27 dream reports in which they asked dream character...
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In lucid dreams the dreamer is aware that he or she is dreaming. Although such dreams are not that uncommon, many aspects of lucid dream phenomenology are still unclear. An online survey was conducted to gather data about lucid dream origination, duration, active or passive participation in the dream, planned actions for lucid dreams, and other phe...
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In a lucid dream the dreamer is aware of the dream state. Previous research has shown that external stimuli (e.g. flashing lights) presented to a person during REM sleep can trigger lucidity. To further examine the possibility of lucid dream induction by external stimulation, visual and tactile stimuli were investigated in an exploratory sleep labo...
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Purpose The purpose of this study was to evaluate whether and to what extent the observed effects on self-rated sleep in a previous study using a combined treatment program with physical exercise and sleep education can be attributed by the physical activity (PA) component. Methods The present study reports supplementary analysis of an already des...
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Lucid dream and nightmare frequencies vary greatly between individuals and reliable instruments are needed to assess these differences. The present study aimed to examine the reliability of eight-point scales for measuring lucid dream and nightmare frequencies. The scales were administered twice (with a four-week interval) to 93 sport students. A r...
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Home dream recall frequencies and nightmare frequencies show great inter-individual differences. Most of the studies trying to explain these differences, however, studied young participants, so these findings might not be true for persons older than 25 years. The present study investigated the relationship between dream recall, nightmare frequency,...
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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 resear...
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Lucid dreams – dreams in which the dreamer is aware that is dreaming – most frequently occur during REM sleep, yet there is some evidence suggesting that lucid dreaming can occur during NREM sleep as well. By conduct- ing a sleep laboratory study on lucid dreams, we found two possible instances of lucidity during NREM sleep which are reported here....
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Procedural learning benefits from memory processes occurring outside practice resulting in offline learning. Offline gains have been demonstrated almost exclusively for the ordinal structure of sequential motor tasks. Many skills also demand that the correct serial order of events be appropriately timed. Evidence indicates that the temporal aspect...
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Der Schlaf ist eine wichtige Ressource für das psychische und physische Wohlbefinden. Die Erkenntnisse aus der Schlafforschung spielten jedoch in der Sportwissenschaft bislang nur eine untergeordnete Rolle. Nach einer kurzen Einführung zur physiologischen Erfassung von Schlaf werden in diesem Beitrag drei Bereiche aufgeführt, die fruchtbare Verknüp...
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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...
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Important sports events are highlights and stressful situations in every athlete's career. This stress might alter the dream content of athletes and consequently evoke disturbed dreaming. In this study, the authors asked 840 German athletes from various sports about distressing dreams on the nights before an important competition or game. About 15%...
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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 a...
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Sleep is generally regarded as a valuable resource for psychological and physiological well-being. Although the effects of sleep on athletic performance have been acknowledged in sport science, few studies have investigated the prevalence of sleep problems and their effects on elite athletes before a sport event. In this study, 632 German athletes...
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In dreams we usually interact with other dream characters that seem to talk and behave logically. Lucid dreamers, who are aware that they are dreaming during the dream, can have deliberate conversations with their dream characters and ask them to accomplish specific tasks. Previous studies have shown that dream characters can be creative and ingeni...
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Lucid dreams occur when a person is aware that he is dreaming while he is dreaming. In a representative sample of German adults (N = 919), 51% of the participants reported that they had experienced a lucid dream at least once. Lucid dream recall was significantly higher in women and negatively correlated with age. However, these effects might be ex...
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Mental practice is the cognitive rehearsal of a motor task in the absence of overt physical movement. A different and rather unknown kind of mental rehearsal is practice in lucid dreams. Within lucid dreams, the dreamer is able to control the ongoing dream content and for athletes it is possible to use the dream state to deliberately practice sport...
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Research indicates that physical exercise can contribute to better sleep quality. This study investigates the six-week influence of a combined intervention on self-rated sleep quality, daytime mood, and quality of life. A nonclinical sample of 114 adults with chronic initiating and the maintaining of sleep complaints participated in the study. The...
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Next round for the International Journal of Dream Research.
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Recently, Allan Hobson published a brief essay in which he recognizes that lucid dreams are scientifically relevant and constitute a powerful tool for understanding the neurobiology of consciousness (Hobson, 2009). His statements are mostly based on the study by Voss et al. (2009), which employed refined mathematical analysis of electroencephalogra...
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Zusammenfassung. Das Mentale Training im Sinne der planmasig wiederholten Vorstellung einer motorischen Fertigkeit ist ein zentraler Gegenstand der sportwissenschaftlichen Forschung und eine wichtige Trainingserganzung in der Sportpraxis. Fur das bessere Verstandnis der Trainingswirkung wird in diesem Beitrag vorgeschlagen, Mentales Training als Si...
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After initial learning, sleep enhances performance in spatially defined, repetitive sequential finger tapping skills (e.g. Walker, 2005; Blischke et al., 2008). It is not clear, however, which feature in the motor skill’s memory representation is actually enhanced: (a) the allocentric spatial pattern, or (b) rapidly switching on and off flexor and...
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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 a...
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The International Journal of Dream Research is reaching its third year. The two issues of 2009 included 13 original papers and one invited essay. These articles covered a large variety of topics like lucid dreaming, dream recall, dream content, nightmares, dreams and psychopathology, and sleep quality. Submissions from all over the world including...
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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 in...
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Empirical studies largely support the continuity hypothesis of dreaming. For example, it has been shown in past research that sport students dream more often about sports than psychology students do, presumably reflecting their engagement in sport activities and sport theory. The present study tested the hypothesis whether frequency of sport dreams...
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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 luc...
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In this paper, changes of subjective sleep quality and state anxiety prior to a final sport exam have been investigated. Subjective sleep quality and state anxiety were psychometrically recorded from a group of high-school students one month prior, one week prior and the night before the exam. The high-school students showed higher state anxiety in...
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p> In the field of professional team sports, anecdotal reports about athletes who experience disturbed sleep in the night prior to away games due to changes in the sleep environment have been published. Ten semi-professional female volleyball players participated in the study. Subjective sleep quality was psychometrically recorded prior to a home g...
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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 (per...
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The continuity hypothesis in its general form states that dreams reflect waking life: concerns, thoughts, and experiences (G. W. Domhoff, 1996; M. Schredl, 1999; I. Strauch & B. Meier, 1996). For example, athletes and sport students dream about sports more often than do psychology students, presumably reflecting their engagement in sport activities...
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The present study investigated the incidence of lucid dreaming within a Japanese university student sample. From 153 Japanese students 47% reported experiencing a lucid dream at least once and 19% were frequent lucid dreamers (frequency equal or higher than once a month). Dream recall frequency was significantly related to lucid dream frequency. In...
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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...
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During the recent years it has been shown repeatedly that, after initial learning, elapse of time preserves, but sleep enhances performance in procedural motor skills. To date, however, the majority of experimental studies in this area employed some sort of a sequential finger tapping skill as a criterion task. Thus it is unclear yet, if any (and w...