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The effect of sleep position on dream experiences

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Abstract

This study explored whether dream experiences are modulated by body posture during sleep with consideration of Big Five personality dimensions and repressive defensiveness. The Dream Intensity Scale, Dream Motif Scale, NEO Five-Factor Inventory, and Marlowe–Crowne Social Desirability Scale were administered to 670 participants. The results indicate that sleeping in the prone position may promote dreaming of sexual, erotomaniac, and persecutory material, such as themes involving “having a sexual relationship with a big wheel or celebrity,” “being smothered, unable to breathe,” “being locked up,” and “being tied, unable to move.” This effect cannot be fully explained by personality factors, which are merely weakly associated with sleep position. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

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... The literature is scarce in terms of studies that analyze the influence of adopted body position and sleep quality (Agargun, Boysan, & Hanoglu, 2004;De Koninck, Gagnon, & Lallier, 1983;Gordon, Grimmer, & Trott, 2004;Nojiri, Okumura, & Ito, 2014;Yu, 2012). The first work to relate sleeping body posture (right side versus left side) to the presence of nightmares or dreams of emotional content and subjective sleep quality, as measured by the Pittsburgh Sleep Quality Index (PSQI) (Agargun et al. 2004), showed that the presence of nightmares was significantly higher in people who slept on the left side (40.9%) compared with those who slept on the right side (14.6%). ...
... In addition, De Koninck et al., (1983) have previously shown that individuals having poor sleep quality spend more time on their backs and with their heads straight in comparison with good sleepers. Subsequently, Yu (2012) reported that the prone position was positively associated with high scores on neuroticism and emotional instability, as well as with the narrative content of disturbing dreams (being locked up, drowning, and unable to move). ...
... With respect to the four positions adopted, similar to the work of De Koninck et al., (1983), Gordon et al., (2004) and Yu (2012) but unlike the RLD and LLD positions explored by Agargun et al. (2004) and the inclusion of the SUD position in the work of Ichijo and Akita (2017)their relationships with the expression of anger are analyzed, which revealed differences between them. The participants who sleep in the PD position showed higher scores than those adopting the RLD and LLD positions on the scales of Feelings of Anger, Trait-Anger, Temperament of Anger, Anger Expression Index, and External Expression of Anger. ...
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Objective: To analyze the subjective quality of sleep and the expression of anger according to the position adopted during sleep. Methods: Using an ex-post facto design and an incidental sampling procedure, 729 university students participated in the study, 63% of which were women. The subjective quality of sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI) and anger was measured using the State-Trait Anger Expression Inventory-2 (STAXI-2). One question was used to determine the body position: "Normally, what position do you adopt when sleeping? [Right Lateral Decubitus (RLD), Left Lateral Decubitus (LLD), Supine Decubitus (SUD), or Prone Decubitus (PD)]. Results: Of our sample, 42.4% reported sleeping in the RLD position, 29.2% in LLD, 10.6% in SUD and 17.8% in PD. Women tended to sleep in RLD and not in SUD, while in men there is a tendency to sleep in the SUD position and not in RLD (χ(3, 729)² =15.119, p=.002). People who reported sleeping in RLD appeared to have poorer quality of sleep compared with the group that reported sleeping in LLD. Those who adopt the PD position show the highest scores on the scales measuring Feelings of Anger, Trait- Anger, Temperament of Anger, Index of Expression of Anger, and External Expression of Anger. Conclusion: The data appear to support the existence of relationships between the posture adopted during sleep, the subjective quality of sleep and emotional states. In future research it will be necessary to apply methodologies with greater control of the variables along with objective measures of body position.
... Numerous studies have shown that sleep postures can serve as an indicator of sleep health. Monitoring in-bed postures provides valuable information regarding the intensity of dreams [3], risk of pressure ulcers [4], patients' mobility [5], obstructive sleep apnea syndrome [6], risk of spinal symptoms [7], and quality of sleep [8]. Therefore, sleep behavior monitoring is a critical aspect of healthcare management. ...
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Sleep quality is known to have a considerable impact on human health. Recent research shows that head and body pose play a vital role in affecting sleep quality. This paper presents a deep multi-task learning network to perform head and upper-body detection and pose classification during sleep. The proposed system has two major advantages: first, it detects and predicts upper-body pose and head pose simultaneously during sleep, and second, it is a contact-free home security camera-based monitoring system that can work on remote subjects, as it uses images captured by a home security camera. In addition, a synopsis of sleep postures is provided for analysis and diagnosis of sleep patterns. Experimental results show that our multi-task model achieves an average of 92.5% accuracy on challenging datasets, yields the best performance compared to the other methods, and obtains 91.7% accuracy on the real-life overnight sleep data. The proposed system can be applied reliably to extensive public sleep data with various covering conditions and is robust to real-life overnight sleep data.
... The sleeper's environment and sensory stimulation during sleep may also impact dream activity and notably its emotional content (2). It is for example the case for sounds (27,28), odors (29,30), and painful stimuli or thirst (31, 32) also for physical bodily position (33). ...
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In order to ensure robust relationships between the dependent and independent variables in clinical dream/nightmare studies, the major factors which influence the frequency of reported dreams must be controlled. This article sets out methodological recommendations to both researchers seeking to ensure the equivalence of experimental groups of participants in group-matching designs, and to clinicians who wish to check that any change in frequency of reported nightmares over the course of a psychological or a pharmacological intervention is not caused by factors other than the experimental treatment itself. The main factors influencing the frequency of dream recall are presented: demographic variables, psychological characteristics, pathological dimensions, and substance consumption. A series of questionnaires is proposed for easily measuring these control variables.
... According to Agargun, Boysan, and Hanoglu (2004), right-side sleepers are more likely to experience better sleep quality and the feelings of relief and safety in dreams and are less likely to suffer nightmares in comparison with left-side sleepers. Likewise, Yu's (2012Yu's ( , 2013 studies indicated that prone sleep, which creates pressure on the front of the body, may promote dreaming of sexual, erotomaniac, and persecutory material, such as themes involving "having a sexual relationship with a prominent person or celebrity, " "being smothered, unable to breathe, " and "being tied, unable to move." This effect cannot be properly accounted for by personality factors, which, similar to the findings reported by Kamau, Luber, and Kumar (2012), were shown to be weakly correlated with sleep position. ...
Article
This study examined whether the proportion of time spent on varying positions could account for the accuracy of self-perceived sleep position. The sample contained 26 healthy subjects, who were invited to sleep at a laboratory for two consecutive nights and in the next morning, were asked to answer some questions about their sleep, including self-perceived major sleep position and other sleep positions adopted. Their sleep was videotaped and was coded by two external judges. For both laboratory nights, subjects who correctly reported their major sleep position spent a larger proportion of their sleep time on the major body position, spent a smaller proportion of their sleep time on positions other than the major one, showed a larger discrepancy between the two proportions, and tended to rest their hands on their chest or stomach during sleep rather than put their hands aside their trunk than did subjects who incorrectly identified their major sleep position. These findings suggest that the misperception of one’s sleep position can be attributed to the individual difference in the variability of sleep positions across the night. Although most subjects could correctly identify their major sleep position, the inaccuracy rate was high – that is, 23.1% for the first laboratory night and 42.3% for the second laboratory night. Furthermore, self-perceived and externally coded sleep positions were not significantly associated in the second night. The self-report method is far less expensive than the video-coding method but researchers should be cautious about its limitations and consistency with objective measures. Since the body posture during sleep is dynamic rather than static and sleepers may not be aware of their position shifts across the night, self-reported sleep position does not necessarily correspond to its objective counterpart, especially for those sleepers whose spend a similar proportion of time lying in different positions across the night. For clinical purposes, therefore, self-report of sleep position should be complemented by video records. Some specific body postures – such as resting hands on the chest and the nose pointing to one side – were demonstrated to be differentially correlated with supine and lateral sleep. Investigators may make use of these additional body postures to improve the accuracy of a reported sleep position.
... have occasionally reported "intruders" or "incubi" that lack the m'Llevoc lent characteristics usually associated with them and are instead perceived as sexually compellh1g. Second, these erotic sensations could be the of son1e degree of direct stimulation or pressure on the sex organs dally when sleepmg in a prone position), which becomes subsequently corporated into the overall ISP experience (e.g., see Yu, 2012). Nc>crrrrn< emissions have been reported durmg ISP as well (e.g., Roscl1e1~ 2007). ...
... In light of the high comorbidity between sleep problems, such as nightmares in insomniacs, RBD and sleepwalking in narcoleptics, and restless legs syndrome in apneoics (American Psychiatric Association, 2013), it was hypothesized that a global score for sleeping problems, as well as scores for dyssomnias and parasomnias in particular, would be positively correlated with scales assessing the intensity and thematic content of participants' dreams. Additionally, 11 specific hypotheses were generated based on three major assumptions: 1) sleep problems, as evidenced by sleep fragmentation and a greater number of awakenings, alter the level of arousal during sleep, 2) the sensory and physiological conditions at sleep can be converted into dream images (see Yu, 2012b) or conversely, dream behaviors are acted out, and 3) dreams reflect the emotions associated with sleep problems. The 11 hypotheses are enumerated as follows: ...
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This study examines the prevalence of men’s sexual behaviors, erotic dreams, and nocturnal emissions and the continuity between diurnal and nocturnal sexuality. On the strength of the findings generated from a survey of 306 young male adults, several important implications are highlighted. Pornography consumption and masturbation with ejaculation are almost universal habits for young men. The form of sexual acts that sleepers dream about reflects the type and incidence of their pornography use and sexual behaviors during wakefulness. Erotic dreams and nocturnal emissions appear to serve as complements to waking-life sexuality. The choice of sexual objects and interactions in the formation of dream images is neither random nor rational, but is egoistic in nature. The most common sexual object that men dream about is not their girlfriend but is their female classmate or acquaintance; receiving sex pleasure by means of the penis being manually or orally stimulated is more likely to happen than giving the parallel sex pleasure to the object in erotic dreams. Certain typical dreams, the manifest content of which does not present any erotic elements, are physiologically arousing to the extent that they can induce the expulsion of semen. In other words, activities commonly occurring in dreams—especially for those about the urgent need to empty one’s bladder and rummaging around for a toilet—can carry the same sexual connotations for men at the biological level. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
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The present study investigated the recurrence of typical dreams and refined Yu's measures for assessing the delusional inclination during dreaming. The Dream Themes Inventory, which consists of typical, delusional, appetitive-instinctual dream themes, was administered to 608 participants. The results indicate that some dream motifs are not only shared by a majority of people but also regularly recur within a person. Moreover, this study demonstrates that virtually all types of delusions and paranoid suspiciousness—including grandiose, persecutory, religious, somatic, jealous, and erotomanic delusions—can be observed in dreams. In addition to fine-tuning Yu's previous Ego Ideal, Grandiosity, and Persecution scales, Erotomania, Appetite-instinct, and Sensorimotor Excitement scales were developed to supplement the assessment of the intrinsic predispositions that modulate dream content. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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This study aimed to examine the influence of specific sleep disorders on dream content. The authors hypothesized that: (a) waking somatic concerns influence dream content and (b) somatic stimulation associated with specific sleep disorders influence dream content items. The subjects (N = 124) were included if they demonstrated obstructive sleep apnea, narcolepsy, an EEG arousal disorder during sleep, or periodic leg movements during sleep (PLMS), based on standard polysomnography. The 42-item Wahler Physical Symptom Inventory was used to quantify somatic concerns. Dream content and frequency was assessed with a 37-item Dream Questionnaire. Ten symptom-dream pairs were selected as mutually relevant and subjected to chi-square analysis. 84.6% of all subjects reported having bad dreams (N = 105). A significant proportion of patients who complain of excessive perspiration dream about perspiring, and significant proportions of those who report difficulty breathing while awake dream about feelings of choking and suffocation. Recurring dreams and dreams of paralysis are significantly more prominent in patients with narcolepsy. Patients with sleep apnea do not dream of choking/feelings of suffocation with greater frequency than nonapneics. These findings suggest that somatic stimulation associated with specific sleep disorders appears to have an inconsistent influence on certain dream content items. Furthermore, dream mentation appears to feature waking concerns, rather that being related to events associated with during sleep disorders. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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The present study explored the clinical utility of the Dream Intensity Scale (DIS) by evaluating the degree to which the components of dream intensity can serve as indicators of the tendencies to hysterical dissociation and conversion, taking neuroticism and psychological boundaries into consideration. The discriminant models constituted by the DIS scales alone differentiated participants who manifested clinically significant dissociative or conversion symptoms from the remaining sample, with the accuracy rate ranging between 67.2% and 71.5%. The discriminative power of the DIS was so impressive that the inclusion in the models of neuroticism, psychological boundaries, and dissociative or conversion levels—the key factors associated with hysteria—raised the correct classification rate by less than 9%. The relationships between neuroticism, boundary thinness, dissociative features, epileptic-like symptoms, and subjective dream intensity were discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
The present study was geared toward generating a parsimonious factor model of typical dreams. Moreover, the hypothesis that themes typically manifest in psychotic delusions also prevail in normal people's dreams was examined. The modified Typical Dreams Questionnaire was administered to a sample of 348 university students from Hong Kong. The factor solutions generated by the current analyses indicate that typical dreams can be classified into three primary categories or six subcategories according to the two-tier model. Consistent with the homology between dreaming and psychosis, the first two categories of the upper tier are, in essence, characterized by the two classic psychotic themes—the grandiose and persecutory delusions. The third category of dream themes consists in the distinctive affective experience that can be, one way or another, attributed to the function of the ego ideal. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
The present study aimed to determine how often Chinese people dream of sexual metaphors and to examine the association between the dreaming of sexual experiences and contemporary Chinese sex symbols. A list of sex symbols was derived from a thorough review of the sexual analogies that Chinese people most often use in slang language. This list, together with the Marlowe-Crowne Social Desirability Scale and the Eysenck Personality Questionnaire Revised-Short Form, was administrated to a sample of 608 upper-secondary school graduates from Hong Kong. It was found that the participants rarely dreamed about food analogies for sex, such as "eating litchis" and "bananas or banana-like objects." By contrast, sex symbols involving weapons and aggressive behavior, such as "knives, swords, or daggers" and "shooting," occurred in dreams with moderate prevalence rates. Moreover, gender, the frequency of dreaming sexual experiences, and social desirability significantly predicted the frequency scores on the scale formed by these aggressive symbols for sex.
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This study examined the extent to which the intrinsic predispositions that modulate dream content serve as indicators of the hysterical tendency to conversion and dissociation. The Dream Themes Inventory, Dream Intensity Scale, Limbic System Checklist-33, Dissociative Experiences Scale, Eysenck Personality Questionnaire Revised-Short Form, Boundary Questionnaire-18, and scales for evaluating defense mechanisms were administered to 585 Chinese participants. The findings indicate that the intensity of dream experiences and the narrative content of dreams are useful for identifying individuals with clinically significant hysterical symptoms. Hysterical dissociation is better predicted by the Ego Ideal, Appetite-Instinctual, and Sexual scales of the Dream Themes Inventory, whereas hysterical conversion is better indicated by the Persecution scale. This finding is discussed in relation to the neuropsychological mechanisms of dreaming and delusions. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Investigated the proposed link between vestibular activation and dream lucidity in 8 university students who spent 2 consecutive nights sleeping in a hammock in the sleep laboratory. For each night, during the 2nd, 3rd, and 4th REM sleep periods, the hammock was either stationary (control condition), or rocked at a constant frequency (experimental condition) stimulating the S's vestibular system. Ss were awakened after 10 min of REM sleep and asked to provide a mentation report that was later analyzed on a number of scales and physiological measures. Results indicate that there was a pronounced increase in both peak self-reflectiveness and lucidity mentation continuum scores associated with rocking in the early morning. Also, rocking can be incorporated into dream imagery, leading to a higher incidence of vestibular imagery and dream bizarreness. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
The Dream Intensity Scale (DIS) is a questionnaire developed for assessing the subjective magnitude of dream experiences. The factorial structure of the DIS measurement model, which was built upon exploratory factor analyses, has not been tested using confirmatory statistics. Therefore, this study was conducted to examine the overall quality of the structural relations among the parameters that constitute the DIS measurement model. Two samples were recruited separately in two consecutive years, and contained a total of 1,186 voluntary participants. The confirmatory statistics indicate that the model hypothesizing four higher-order and eight lower-order factors provides an excellent fit to the data, and is distinguished by its invariance across samples and genders. In addition, the convergent and discriminant concurrent validity of the DIS is substantiated by the differential sensitivity of its scales and subscales to the big-five personality dimensions. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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This study’s primary purpose was to examine the overall quality of the factorial structure of the Dream Intensity Inventory (DII). It was hypothesized that dream intensity was a multifaceted construct that could be accounted for by 3 latent factors, namely Dream Quantity, Dream Vividness, and Altered Dream Episodes. The 1st-order oblique, 1st-order orthogonal, and 2nd-order models, which represented 3 possible versions of the structural relations among the 3 latent factors, were subjected to the confirmatory statistical procedures. The goodness-of-fit indices indicated that the 2nd-order model and the 1st-order model hypothesizing 3 oblique factors were superior to that hypothesizing 3 orthogonal factors. The factorial characteristics of the two well-fitting DII models were shown to be equivalent across 2 samples. These results suggest that the theoretical construct of dream intensity can be pertinently described by the 3-factor measurement model. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
This study examined the degree to which the phenomenological experience of dream intensity and its components are correlated with repression, splitting, and other defense mechanisms. The Dream Intensity Scale, Marlowe-Crowne Social Desirability Scale, Splitting Scale, Defense Style Questionnaire-40, and other related measures were administered to 583 subjects. It is demonstrated that repression as a personality trait is inversely and moderately related to the quantitative aspect of dream intensity (i.e., frequencies of dream awareness, nightmares, and multiple dreams in a single night) but does not influence qualitative sensory experiences in dreams (e.g., hearing sounds in dreams). Moreover, the present findings indicate that the more repressed people are, the less likely they are to report splitting and immature defenses, and the less frequently they experience dreams, with the effect of repression on defenses being greater than that on dream intensity. Accordingly, if both dreams and defense mechanisms are the critical materials to work through in a treatment, then starting with the former may be conducive to the therapeutic progress by provoking less resistance from the client. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
This study provides an overview of the frequencies and narrative features of sex and wet dreams and investigates the incestuous behavior in the manifest content of dreams. A questionnaire specially designed for capturing both quantitative and qualitative aspects of sex and wet dreams was administered to 58 male participants. More than 80% of participants had dreamed about having vaginal intercourse with a woman. Dreaming of sexual interactions other than vaginal intercourse—such as oral sex—was also common. Consistent with the hypothesis that latent sexual motives or some variation of sexuality that people may not be aware of during the daytime would emerge at night through dreaming, both homosexual and incestuous behaviors were observed in dreams. In addition, the finding indicates that sexual thoughts and motives can be represented by symbols in dreams, and dream impressions involving no erotic scenes are capable of eliciting nocturnal emissions. It seems that sex dreams, wet dreams, and nocturnal emissions without erotic imagery or dreaming can be distinguished from each other. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
Three studies examined the relationship between facial contact with a pillow and mood. In the first, 414 undergraduates described their face and body positions when sleeping and upon awakening, and their moods upon awakening. Results indicated that more negative moods were associated with increased facial contact with pillows. Then, 2 experiments manipulated participants' face and body positions while they lay down and listened to affectively neutral prose passages and musical selections. Participants evaluated the passages and music. Results of both experiments showed that increased facial contact with a pillow led to more negative evaluations. It is argued that these findings reflect effects of facial contact on mood, and are consistent with the facial feedback hypothesis. Possible alternative explanations are considered.
Article
Question of the study There are conflicting findings regarding dream recall frequency (DRF) in patients with sleep-disordered breathing: Various studies have reported less, equal, or higher DRF in comparison with healthy controls. Although more negatively toned dreams were found in these patients, nightmare frequency had not been found to be increased in a previous study. This study concerned whether DRF or nightmare frequency was altered in patients with sleep-disordered breathing without other comorbid diagnoses and whether disorder-related parameters, comorbidity, or drug intake was associated with DRF and nightmare frequency. Patients and methods The present study assessed home DRF and nightmare frequency via two rating scales in 1,706 patients with sleep-disordered breathing. These data were compared with those of healthy control samples from other studies. Results In comparison with the control group, a reduced DRF was found that was not associated with respiratory parameters or comorbidity. Similarly, nightmare frequency was reduced, and one might speculate whether these findings can be explained by cognitive dysfunction, which is often found in patients with sleep-disordered breathing. Use of antidepressants and psychiatric comorbidity were associated with heightened nightmare frequency. Conclusions Future studies should include current medication intake, measures of cognitive functioning, and sleep parameters in order to explain reduced DRF and reduced nightmare frequency in patients with sleep-disordered breathing.
Article
To assess whether obstructive sleep apnea syndrome (OSAS) affects sleep architecture and quality in East Asian children, and also to assess the effects of body position during sleep on respiratory disturbance during sleep. We enrolled 50 consecutive East Asian children with habitual snoring between 2007 and 2009. Nineteen children had OSAS (apnea-hypopnea index, AHI≥5; OSAS group) and 31 children were simple snorers (control group). They underwent polysomnography and physical examination of their nasal and oral cavities with a roentgenogram of the nasopharynx. Sleep architecture and other polysomnographic variables were compared between the OSAS and control groups. The effect of body position during sleep on respiratory disturbance was examined, and also in relation to obesity and adeno-tonsillar size. There was a decrease in total sleep time and in sleep efficiency, as well as increased arousal and heart rate (P<0.05) in the OSAS group. Sub-analysis of AHI according to sleep posture showed that AHI is higher when the patient is in the supine position than in the non-supine position (P=0.032). The presence of OSAS and kissing tonsils were contributing factors to the positional difference in AHI (P<0.05). Obesity and adenoid hypertrophy did not affect the positional difference of AHI. OSAS may have a greater influence on the sleep architecture of East Asian children, and East Asian children may have a higher AHI when sleeping in the supine position. Tonsillar hypertrophy and the presence of OSAS are possible contributing factors for positional difference of AHI in East Asian children.
Article
Dreaming is defined as mental activity which occurs during sleep. This review will focus on sleep disorders which have been studied in relation to dreaming: insomnia, sleep apnea syndrome, narcolepsy, and the restless legs syndrome. Dream recall is heightened in patients with insomnia and their dreams reflect current stressors. Whereas breathing-related dreams in sleep apnea patients are rare, the deregulation of the REM sleep system in narcolepsy also manifests in dreams which are more bizarre and more negatively toned. Overall, the findings support the arousal-retrieval model of dream recall but also clearly indicate that other factors like cognitive impairment or micro-arousal might affect the dreaming process. The content analytic findings support the continuity hypothesis of dreaming which states that waking-life issues are reflected in dreams. The number of studies in this field is still very small, however, and further research is needed to confirm and expand the reviewed findings.
Article
THE NUMEROUS anecdotal accounts of incorporations of naturally occurring external and internal stimuli (falling out of bed, thunder, stomachaches, etc) into dreams,1-4 as well as some early, systematic studies,5-7 attest to man's continuing interest in the nature of his commerce with the environment during sleep. Dement and Wolpert8 studied the effects of three different types of stimuli (water spray, light, and pure tone) on dreams. They presented the various stimuli during rapid eye movement (REM) periods, the stage of sleep from which dream reports are most often elicited on awakening,9-12 and found the tactile stimulus (water) to be the most potent, being incorporated 42% of the time as compared to 9% for the tone and 23% for the light. Berger13 obtained over 50% incorporation for both meaningful and nonmeaningful names. The immense discrepancy between the amount of incorporation of an auditory
Article
The purpose of this investigation was to investigate, in high-risk infants, the occurrence of abnormalities in documented monitor downloads during the side versus prone position. Forty infants admitted to the A. I. duPont Hospital for Children with diagnoses associated with sudden infant death syndrome were included in this investigation. During an overnight hospitalization, infants were placed on home apnea monitors, with computer memory to capture alarms for apnea > 20 seconds, age-defined bradycardia, and tachycardia. Infants were studied for 12 hours. Each infant was assigned to 6 hours of prone and side during the 12-hour period, with order of position randomly assigned by random number generation. Differences between the two positions in alarm frequency and significant events, as determined by a blinded interpreting physician were analyzed by Fisher exact test, with p < 0.05. Power analysis necessitated 20 patients in each group, with beta error of 0.2. Eleven episodes of apnea occurred in the prone position, and 16 in the side position (p = NS). The mean numbers of apnea events per tracing in the prone position was 0.27 +/- 0.84 and 0.39 +/- 1.1 in the side position (p = 0.58). The mean number of bradycardia events per tracing in the prone position was 0.44 +/- 1.45 and 0.49 +/- 1.94 in the side position (p = 0.9). Clinicians need to be cautious when recommending the side or prone position in this group of high-risk infants. The results in this investigation provide support for the Back to Sleep Campaign recommendations to be applied, not only to healthy term infants, but higher risk infants as well. Studies of the high-risk infant in the supine position are warranted.
Article
Sleep paralysis (SP) entails a period of paralysis upon waking or falling asleep and is often accompanied by terrifying hallucinations. Two situational conditions for sleep paralysis, body position (supine, prone, and left or right lateral decubitus) and timing (beginning, middle, or end of sleep), were investigated in two studies involving 6730 subjects, including 4699 SP experients. A greater number of individuals reported SP in the supine position than all other positions combined. The supine position was also 3-4 times more common during SP than when normally falling asleep. The supine position during SP was reported to be more prevalent at the middle and end of sleep than at the beginning suggesting that the SP episodes at the later times might arise from brief microarousals during REM, possibly induced by apnea. Reported frequency of SP was also greater among those consistently reporting episodes at the beginning and middle of sleep than among those reporting episodes when waking up at the end of sleep. The effects of position and timing of SP on the nature of hallucinations that accompany SP were also examined. Modest effects were found for SP timing, but not body position, and the reported intensity of hallucinations and fear during SP. Thus, body position and timing of SP episodes appear to affect both the incidence and, to a lesser extent, the quality of the SP experience.
Article
-Three Ss slept with their eyes taped open and their pupils chemically dilated while stages of sleep were monitored by EEG and eye movement recordings. Various objects were illuminated in front of Ss' open eyes. Shoctly following the stimulus presentarions, Ss were awakened and reports of dream experiences and other imagery during sleep were obtained. Although there were occasional instances of dream imagery containing light stimulation, there was essentially no evidence for a correspondence between the reported imagery and the specific characteristics of the stimulus objects. The relative functional blindness of sleep fails to support theories stating that dream images are determined by patterns of retinal excitation.
Article
To study dream content in patients with severe obstructive sleep apnea syndrome (OSAS) and its modification with Continuous Positive Airway Pressure (CPAP) therapy. We assessed twenty consecutive patients with severe OSAS and 17 healthy controls. Polysomnograms were recorded at baseline in patients and controls and during the CPAP titration night, 3 months after effective treatment and 2 years later in patients. Subjects were awakened 5-10 min after the beginning of the first and last rapid eye movement (REM) sleep periods and we measured percentage of dream recall, emotional content of the dream, word count, thematic units, sleep architecture and REM density. Dream recall in REM sleep was similar in patients at baseline and controls (51.5% versus 44.4% respectively; P = .421), decreased to 20% and 24.3% the first and third month CPAP nights, and increased to 39% 2 years later (P = 0.004). Violent/highly anxious dreams were only seen in patients at baseline. Word count was higher in patients than in controls. REM density was highest the first CPAP night. Severe OSAS patients recall dreams in REM sleep as often as controls, but their dreams have an increased emotional tone and are longer. Despite an increase in REM density, dream recall decreased the first months of CPAP and recovered 2 years later. Violent/highly anxious dreams disappeared with treatment. A dream recall decrease with CPAP is associated with normalization of sleep in OSAS patients.
Article
The interaction of sensory physiology and sleep has been studied for various sensory systems. Nevertheless, the question whether chemosensory (especially olfactory) stimuli may lead to arousals during sleep remains under discussion. Specifically, the central processing of olfactory information shows fundamental differences compared to other sensory systems. Prospective controlled trial. Sleep research facility, University Hospital. Five young healthy, normosmic volunteers. Intranasal chemosensory stimulation during sleep was based on air-dilution olfactometry. For olfactory stimulation H2S (smell of rotten eggs) was used in 4 concentrations (1, 2, 4, and 8 ppm). For trigeminal stimulation CO2 (stinging sensation) was also administered in 4 concentrations (10%, 20%, 40%, and 60% v/v) while odorless stimuli were used for control. Arousal reactions due to chemosensory stimulation were assessed during overnight polysomnography 30 seconds after the presentation of every stimulus during 23 nights of testing. For olfactory testing, an average number of 703 olfactory stimuli and 157 odorless controls were used for analysis per subject. Even the highest stimulus concentration did not produce an increase in arousal frequency. For trigeminal testing, an average number of 405 stimuli and 79 controls were used for analysis per subject, and an increase in arousal frequency was observed following the increase of stimulus concentration. With the present results we were able to demonstrate that, in contrast to trigeminal stimulation, the presentation of a strong but selective olfactory stimulus does not lead to arousals during nocturnal sleep in humans.
REM-associated hallucinations and sleep paralysis are dependent on body posture The relation of eye movements, body motility, and external stimuli to dream content
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  • M Kasten
  • W Dement
  • E A Wolpert
Dahmen, N., & Kasten, M. (2001). REM-associated hallucinations and sleep paralysis are dependent on body posture. Journal of Neurology, 248, 423–424. doi:10.1007/s004150170186 Dement, W., & Wolpert, E. A. (1958). The relation of eye movements, body motility, and external stimuli to dream content. Journal of Experimental Psychology, 55, 543–553. h0040031;/Border
Sleep positions and personality: An empirical study
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Schredl, M. (2002). Sleep positions and personality: An empirical study. North American Journal of Psychology, 4, 129 –132.
Information processing during sleep: The effect of olfactory stimuli on dream content and dream emotions doi:10.1111/j.1365-2869 Dream recall frequency and nightmare frequency in patients with sleep-disordered breathing
  • M Schmitt
Information processing during sleep: The effect of olfactory stimuli on dream content and dream emotions. Journal of Sleep Research, 18, 285–290. doi:10.1111/j.1365-2869.2009.00737.x Schredl, M., & Schmitt, J. (2009). Dream recall frequency and nightmare frequency in patients with sleep-disordered breathing. Somnologie, 13, 12–17. doi:10.1007/s11818-008-0359-3