Assessing the dream-lag effect for REM and NREM stage 2 dreams

This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5-7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.     

Austrian Dream Behavior: Results of a Representative Population Survey

This study was based on a survey of a representative sample of 1000 Austrians who were questioned about their sleep and dream behavior. About two-thirds of the respondents reported that they generally recalled at least one dream per month. Dream recall frequency decreased with advancing age, but did not differ between men and women. Fifty-five percent of the respondents characterized the affective content of their dreams: 29% reported neutral, 20% positive, and 6% negative dreams. Four percent of the sample reported suffering from nightmares. These respondents more frequently reported snoring, interrupted sleep, daytime somnolence, anxiety and nervousness, depression, high dream recall, recurrent dreams, and dreaming in color. Twenty-six percent of the total sample reported that sometimes they realized during their dreams that they were dreaming. These respondents more frequently reported family problems, high dream recall, positive dream content, recurrent dreams, dreaming in color, and nightmares.     

Masochistic Dreams: A Gender-Related Diathesis for Depression Revisited

Masochistic dreams, as defined by Beck (1967), are reportedly more prevalent among women and individuals with past or present depression. However, it is unclear whether these prevalence differences are a function of depressogenic personality traits or fluctuating mood symptoms. In the present study, 30 men and 30 women without histories of major depression slept two consecutive nights in a sleep laboratory and reported their dreams from each REM period on the second night. Dream content from this sample was compared to that of 60 depressed participants who were studied previously under the same protocol. Analyses did not support a heightened prevalence of masochistic dreams among women or depressed individuals. Interestingly, the masochistic dreams of the non-depressed sample were equally distributed across the night, whereas depressed individuals tend to report masochistic dreams closer to morning. This hypothesized pattern suggests that masochistic dreams may be pathognomic of depression in that their occurrence near the end of the night affects morning mood with negative dream residue.     

Questionnaires and Diaries as Research Instruments in Dream Research: Methodological Issues

Dream questionnaires are widely used in dream research to measure dream recall frequency and various aspects of dream life. The present study has investigated the intercorrelation between questionnaire and diary measures. 285 participants completed a dream questionnaire and kept a dream diary over a two-week period. Results indicate that keeping a dream diary increased dream recall in low and medium dream recallers but decreased dream recall in high dream recallers. The correlation coefficients between questionnaire items measuring aspects of dream content and diary data were large, except for a more complex scale (realism/bizarreness). In the low recall group, however, considerably lower coefficients were found indicating that recall and sampling processes affect the response to global items measuring dream content. Using the example of testing gender differences, the findings of the present study clearly indicate that the measurement technique affects the results. Whereas sufficient internal consistency and retest reliability have been demonstrated for various dream questionnaires, future research should focus on the aspects of validity by comparing questionnaire data to dream content analysis of at least 20 dreams per person.     

Dream Intensity Inventory and Chinese people's dream experience frequencies.

The present study aimed to devise a parsimonious instrument for evaluating both the quantitative and qualitative aspects of dream experiences and to quantify Chinese people's dream experiences in ways that facilitated cross-cultural comparisons. The Dream Intensity Inventory was developed and administered to 348 Chinese university students. Individual differences in dream recall frequency were observed, with some participants recalling dreams almost every morning whereas others recalled dreams less than once a month. By contrast, the Chinese participants exhibited less diverse dream awareness frequencies. Multiple dreams in a single night and nightmares were found to be prevalent among the Chinese participants. On the other hand, fewer than half of the participants experienced regularly voluntary control over dream activities and consciousness. The factor analyses of the items in the Dream Intensity Inventory resulted in three readily interpreted factors, which were labeled as the "dream quantity," "altered dream episodes," and "dream vividness" subscales, respectively. When compared with men, women participants had higher frequencies of regular dream experiences including dream awareness, nightmares, and multiple dreams, as measured by the dream quantity subscale. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream Interpretation in Ancient Civilizations

Dream interpretation was regarded by ancient peoples in Mesopotamia, Egypt, Greece, and Rome as an art requiring intelligence and, sometimes, divine inspiration. It became a motif in literature. It was treated as a science by philosophers and physicians. Dreams were thought to come either as clear messages, or as symbols requiring interpretation. In a method called incubation, the dreamer could sleep in a sacred place in expectation of a dream that would elucidate a problem for which the dreamer desired guidance. Dream-books listing images and their meanings were popular. Historians reported leaders' famous dreams that affected the course of events. Very few ancient writers were skeptical of dreams; Cicero was one. Dream interpretation was an honored profession with exponents such as Artemidorus of Daldis. Ancient dream traditions and beliefs can provide perspective for consideration of more recent theories of dream interpretation.     

Dream Recall Frequency and Dream Detail as Mediated by Personality, Behavior, and Attitude

Many studies investigated how personality, behavior, and attitude mediate dream recall, but few distinguish between measures of dream recall frequency: the number of dreams experienced in a specified time frame and dream detail: individual ratings of vividness or detailed content of dreams. This study compared undergraduates' (n = 173) self-reported dream recall frequency, and dream detail, with behaviors, attitude toward dreaming, and scores on scales of Extraversion/Introversion and Type A/B. Dream recall frequency and dream detail manifested different patterns of association in relation to behaviors, attitude and personality. Dream recall frequency was associated with the frequency of experiencing emotionally disturbing dreams and trying to interpret dreams, while detail of dreams was associated with positive attitude toward dreaming and Type B personality. Although males and females both held positive attitudes toward dreaming, females experienced more emotionally disturbing dreams and felt unable to control their dreams. Interactions between personality and gender emerged for behaviors associated with dreaming. Researchers are encouraged to differentiate between dream recall frequency and dream detail.     

Dream reports of animal rights activists.

This study examined the nighttime dream experiences of animal rights activists. The sample consisted of 284 activists who attended the Animal Rights 2004 conference. Participants completed the C. S. Hall and R. Van de Castle (1966) Most Recent Dream Survey (as cited in Domhoff, 1996). The data on dreams were compared with statistical norms on dream content developed by C. S. Hall and R. Van de Castle (as cited in Domhoff, 1996). Results indicated that activists reported animal dream characters at a much higher rate than the general population. Activists also overwhelmingly had more friendly animal dreams than did the general public. Examples of dream reports, as well as the variety of animal species, are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream and blog content analysis of a long term diary of a video game player with obsessive compulsive disorder.

A case study of a young man who is an avid video game player and designer is the focus of this paper. His online Website offers over 800 dreams, of which over half were content analyzed using the Hall and Van de Castle system. Also available were daily blogs. Thus, several research questions could be addressed. Did the diary evidence consistency across time? Did the dreams evidence incorporation of activities discussed in the daily blogs from the day before the dream? Did this one individual's dream diary echo former research into the dreams of video game players? A final question was addressed because of the diagnosis of the diarist as having Obsessive Compulsive Disorder (OCD). Did the dreams of this young man echo previous research into dreams of OCD sufferers? The findings were that the diary was consistent across time and there was incorporation of some elements of the daily blog into subsequent dreams. Some aspects of his dreams echoed previous video game players' dream findings, like more dead and imaginary characters. Finally, the OCD analysis only partly replicated the previous research into the dreams of those with OCD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A relationship between nightmare content and somatic stimuli in a sleep-disordered population: A preliminary study.

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) 2010 APA, all rights reserved)     

Dream Content and Personality: Thick vs. Thin Boundaries

Using dream diary procedures and statistically controlling for age and gender, the present study investigated the relationship between Hartmann's (1991) boundary concept and various aspects of dreaming. Results with a sample of young adults confirmed earlier findings that persons with thin boundaries recall dreams (including nightmares) more often, report dreams that are more negative and emotionally intense, regard their dreams more favorably (i.e., as more meaningful and creative), and dream more frequently of verbal interaction with others.     

Ordinary and Recurrent Dream Recall of Active, Past and Non-recurrent Dreamers During and After Academic Stress

The role of stress in the onset and frequency of recurrent dreams was investigated by comparing dream recall of students undergoing naturalistic stress conditions. Thirty nine students in active, past and non-recurrent dream groups (n = 13) recorded frequency of nights per week involving overall and recurrent dream recall in the week prior to mid-term examinations and in a neutral study week in second semester. Self-report measures of everyday hassles and uplifts, anxiety and positive and negative affect experienced during these conditions were also collected. Anxiety and negative affect were reported as significantly higher in the pre-examination week. Overall the groups reported dreams on significantly more nights in the pre-examination week than the post examination week. Recurrent dream nights increased during the stress week for the active recurrent dream group but there was no change in recurrent dream recall for the other groups. These findings are consistent with theories that the experience of emotional stress is a critical factor in the onset and persistence of recurrent dreams.     

The Relationship of Dream Content and Changes in Daytime Mood in Traumatized vs. Non-Traumatized Children

The study examined how the mood changes from night to morning, and how dysphoric dream contents associate with this change among children who live in traumatic environment and their controls from peaceful area. The sample consisted of 413 Palestinian boys and girls of 6–15 years of age, the mean age being 11.22 ± 2.64. The participants filled in a seven-day dream diary in which they recorded their recalled dreams every morning. First, the results, confirmed that mood change from evening to morning is a general dream function: age and gender are not related to the change. The mood chance was rather associated with what and whom the children dreamt about. Second, the hypothesis of the trauma group showing less change in dysphoric dream content and in the intensity of negative morning mood across a period of time of seven days was not confirmed. On the contrary, the results showed that both dreams incorporating dysphoric themes and negative morning mood decreased only among children living in traumatic conditions. Third, it was hypothesized that there is a stronger association between presleep negative mood and dysphoric dreams, as well as between the dysphoric dreams and negative morning mood among children living in traumatic environment than among children from peaceful area. Contrary to the hypothesis, results for the trauma group revealed a reverse association between evening mood and dream contents: the more afraid, angry and worried children felt in the evening, the more Happy recreation dreams they reported, and the happier evening mood they reported, the more Threatening stranger dreams they had. However, concurring with the hypothesis, a direct association was found between dysphoric dreams and negative morning mood in the trauma group. The more children dreamt about Threatening strangers, the more afraid, angry and worried they felt in the morning. The discussion proposes a model of the correcting or balancing dream function that is characterized by an reverse assimilation of incorporating evening mood into dreams, and by a direct accommodation of dream content into morning mood.     

Dream recall after night awakenings from tonic/phasic REM sleep

Eleven healthy subjects, 9 females and 2 males aged 21-23, were submitted to all night polygraphic recording and awaken in REM (Rapid Eye Movements) sleep, randomly upon tonic or phasic REM. Immediately upon awakening subjects were asked about possible dreaming according to the standardized questionnaire. Seventy-seven dreams, i.e. 79% of all 97 REM awakenings, were reported and analyzed. There were no significant differences in reported frequency of dreamings after awakening, mood and dream content due to phasic/tonic REM sleep. Dreams from phasic REM were a bit more colorful. Predictor of morning remembering of dreams was meaninglessness, not meaningfulness of dreams, and, in lesser extent, good mood, colorfulness, dreams with words and phasic REM sleep.     

The Dream Pun: What Is a Play on Words without Words?

This paper reviews punning in dreams as described in a popular 1974 book by Ann Faraday, The Dream Game. The reasons for undertaking this analysis are threefold. The first reason is to show that dream puns are all based on either homonymy or polysemy and seem to have the purpose of representing abstract thought in concrete form. The second reason is to point out that dream puns are dependent upon a specifically linguistic relationship, a mapping between the concrete and abstract senses of some linguistic data; a direct word-image relation is impossible. The third reason is to suggest that our linguistic minds create dream puns while we sleep, continuing the mind chatter of the previous day.     

Daytime noise and subsequent night sleep in man

The effects of daytime noise on recovery processes during subsequent undisturbed night sleep were studied in six healthy men (21-27 years), exposed to 80 dB (A) pink noise 8 h per day for 2 days. Sleep EEG, ECG, and respiration were recorded in the laboratory for five consecutive nights: two baseline nights, two nights following noise stimulation, and again one baseline night. Additionally questionnaire data were collected, reflecting a subjective impairment of the recovery function of sleep after noise exposure. EEG sleep data of the first post-noise night showed an increase in slow wave sleep with a simultaneous decrease in stage 2 sleep. During the second post-noise night these changes were less prominent. Three subjects additionally showed an instability in the sleep course coinciding with elevated heart and respiration rates. However, altogether the autonomic parameters were not clearly affected by the noise exposure. The findings support the assumption that strong daytime noise may interfere with subsequent sleep processes.     

Comparison of dream anxiety and subjective sleep quality between chronotypes

Morning and evening-type individuals differ on a number of psychological and biological variables. In this study, we aimed to investigate the relationship between sleep quality, dream anxiety, and chronotypes. A sample of 264 university students, aged between 17 and 26 years, completed the Morningness-Eveningness Questionnaire, the Pittsburgh Sleep Quality Index, and the Van Dream Anxiety Scale for assessing nightmare frequency and the dream anxiety caused by frightening dreams. Main findings indicated that evening-type individuals were significantly more likely to suffer from poor sleep quality, daytime dysfunction, nightmares, and nightmare-related disturbances as compared to either intermediate- or morning-type individuals. Previous studies have pointed out the possible connections of irregular sleep-wake habits and circadian dysregulation with a tendency to reveal eveningness chronotypical characteristics. Current findings suggest that evening-type individuals are more prone to experience psychologically deteriorating nightmares and sleep-related anxiety. Poor sleep quality is also a significant antecedent of dream anxiety after controlling for age and gender.

     

Dream contents and failing memories

Mentation during sleep states is thought to originate in an activation of brain circuits that encode inherited and experiential memories. Spontaneous degradation of the strengths of synapses occurs in all brain circuits because of "turnover" of molecules essential for synaptic function. In circuits employed frequently during waking, synaptic strengths are refreshed and maintained in their dedicated or functional ranges largely through use, by virtue of activity-dependent synaptic plasticity. In circuits employed infrequently during waking, synaptic strengths are refreshed largely during sleep, by circuit activations induced by spontaneous, self-generated, largely low-frequency brain waves, also by virtue of activity-dependent synaptic plasticity. The outputs of circuits activated during sleep do not necessarily rise to the level of 'unconscious' awareness. Such an absence of awareness of the outputs of individual circuits, that is, an absence of dreaming, is proposed to be the primitive condition in animals that sleep. On the other hand, temporal binding of these outputs is accompanied by the thoughts and perceptions of dreams, which is proposed to be the advanced condition. Linking or serial ordering of otherwise 'static' thoughts and perceptions gives rise to continuous, often narrative and veridical, dreams. In all cases, dream contents are derived from the memories--not necessarily veridical--encoded in the reinforced circuitry. In the absence of synaptic strength refreshments during sleep, synaptic strengths in infrequently used circuits would weaken and the circuits would become incompetent, with their encoded memories degraded or lost. Maintenance of synaptic strengths in infrequently used circuitry during sleep apparently does not always achieve perfection. Weakened synapses begin to occur in circuits in appreciable numbers in children after the age of about 5 years. When these 'incompetent' circuits (with weakened synapses) are activated during sleep, there are minimal influences on dream contents, namely, distortions that make some objects, such as animals, faces, and scenes, unrecognizable. As weakened synapses increase in numbers with age, the numbers of distorted objects in dreams also increase. In adults, people in as many as 80% of dreams may be unrecognizable. Besides the normal weakening of synaptic strengths, some synapses become defective, in consequence of deleterious, adventitious, exogenous influences, for example, radiation. As these faulty synapses accumulate in old memories, activation of circuits incorporating them during sleep leads to dreams with incoherent, bizarre, or impossible contents. The infrequent activation of such old, incompetent circuits in some waking conditions leads to false memories, delusions, or hallucinations.     

Dream content: Reflections of the emotional and psychological states of earthquake survivors.

This study investigated dream narratives as reflections of the emotional and psychological states of earthquake survivors. Dreams and dreams imagery have reportedly been affected by the emotional and psychological trauma that the dreamer goes through. Dream narratives and dream content ratings used in earlier studies were utilized in this study. Narratives and content ratings were obtained from a sample of 27 volunteer survivors of the October 8, 2005 earthquake in Pakistan (Azad Kashmir area) and 27 volunteer controls from similar demographics. Three independent raters judged the dream narratives and dream content ratings. The judges rating were highly congruent (86.05). Findings revealed that the survivor group had more vivid, unpleasant, horrifying, and hostile dreams compared with the control group. However, there were no significant gender differences. The data suggest that a closer study of dreams can be used to understand the underlying trauma for effective interventions. In addition, interesting emergence of recurrent dreams was seen, which will be independently studied in future. (PsycINFO Database Record (c) 2010 APA, all rights reserved)