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.     

Dream content and memory processing: Dream lag effects within a single night and across several nights: A pilot study.

Dream content may reflect elements of memory processing occurring within a single night and across several days or weeks. One 19-year-old healthy female college student kept a daily diary, a sleep diary, and recorded her dreams for 2 months. A preset alarm clock allowed her to sample dreams from both early NREM-rich and late REM-rich sleep. Dreams were examined for memory elements that were similar to diary entries. There were 55 scorable dreams obtained during 25 nights. Matches between dream elements and daytime events occurred quite frequently depending on dream element. Dream characters, actions, themes, and settings more often matched daytime memories than dream objects, emotions, or events. Matches were also time dependent. Emotions appeared in dreams after the subject experienced them sooner than all other elements (1.5 days), while objects took the longest to appear in dreams (3.5 days). With respect to within night cognitive processing, 42% of scorable nights contained the same memory elements in the first and last dreams and 8% of scorable nights contained the same emotion within the same context between an early and late dream. Selected dream elements appear to reflect memory processing occurring throughout the night and over the course of several days. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between video game play and threat simulation dreams.

Revonsuo proposes an evolutionary theory of dreaming in which dreams allow an individual to prepare for real world threats in the safety of the virtual setting of the dream world. Based upon previous work examining the dreams of video game players, it was hypothesized that high-end gamers would experience fewer threat simulation dreams because of frequent threat resolution rehearsal during game play. Subjects were asked to report a night before dream and fill out surveys regarding their gaming history, media use, and dream experiences. Using a factor analysis, support for the main hypothesis was found. Individuals with a history of game play experienced fewer threat severity variables in their dreams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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 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.     

Electronic media and lucid-control dreams: Morning after reports.

Lucid dreams, as well as control dreams, have recently been reported as associated with video game play (Gackenbach, 2006). In this study, dreams were collected from the morning after a night of rested sleep as well as electronic media use from the day before the dream. In a factor analysis, lucid and control dreams were associated with all electronic media use but most strongly with video game play. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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

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

Attachment styles and emotional content, stress, and conflict in dreams of romantic partners.

Expanding on previous research investigating the link between dreams and attachment, participants in committed dating relationships were recruited to fill out dream diaries for 1 week. It was hypothesized that when dreaming about romantic partners (attachment figures), dream content would vary by attachment style, such that insecurely attached individuals would experience a different quality of dream, emotionally and cognitively. At Time 1, participants completed a self-report measure of attachment style, and then completed a dream diary at home each morning for 7 days. Dreams that contained romantic partners were coded by double-blind research assistants for emotional content, with a focus on attachment-related emotions and stressful expressions. Anxious-attached and avoidant-attached participants experienced significantly more stress and conflict, and scored significantly higher on specific emotions such as anxiety and jealousy in such dreams. Secure scores did not correlate with any specific or general emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream Recall Frequency, Attitude Towards Dreams and Openness to Experience

The question whether personality dimensions explain the interindividual differences in dream recall frequency has often been investigated by dream researchers. The present findings confirm previous research which has shown that traits such as openness-to-experience and thin boundaries correlate substantially with dream recall frequency. However, correlation coefficients are small and are much larger if attitude towards dreams or a scale measuring different aspects of dream recall are considered. Thus, future studies should consider the differentiation between items measuring dream recall and related aspects and items measuring attitudes towards dreams. Schonbar's life-style hypothesis should be revised slightly: not dream recall frequency but attitude towards dreams and the way to deal with dreams are part of a broader life style.     

Children's Dreams and Nightmares: Emerging Trends in Research.

New manifest content analysis research on children's dreams and nightmares provides insights into how dreaming reveals developmental changes over time. Five culturally diverse research studies were conducted with varied methods for dream collection that included laboratory-collected dreams, as well as written journals, audiotaped dreams, and retrospectively recalled dreams. As children grow older, they are more able to recall dreams, dream narratives increase in length, and dreams are characterized by decreasing levels of passive victimization and have more elaborate character interactions. Age and gender differences in recall, interactions, and gender of dream characters indicate that dream research is a fertile area for studying child development and the changing function of dreams over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dream incorporation of video-game play as a function of interactivity and fidelity.

Video-game play offers the opportunity to investigate the continuity hypothesis. Using interactive video games rather than passive films as a controlled manipulation allows for an engaging presleep experience. Several researchers have successfully used video games to investigate dream incorporation. In this study, interactivity and fidelity were the independent measures that manipulated immersion in a commercially available video game. Interactivity was either passive or active, whereas fidelity was high-screen resolution and stereophonic headset audio versus low. The highest dream incorporation in the high-fidelity–high-interactivity condition was expected. Incorporation was assessed by participant self-report and judges' evaluations. The independent variable of fidelity was especially strong in both the manipulation and the subsequent dream incorporation for self-report. Interactivity became the dominant variable when viewed from the judges' perspectives. The effects of demand characteristics and emotionality were also considered. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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.     

Rehearsal of dreams and waking events similarly improves the quality but not the quantity of autobiographical recall.

Salient dreams are often discussed and ruminated upon over time, especially when they feature in dream work or therapy. The present study investigated the effects of rehearsal over time on dream memories, as compared to memories for waking experiences. Participants were instructed to complete a dream and waking episodic event diary over two weeks. A rehearsal group (n = 27) were instructed to read through their reports after recording them. A control group (n = 28) were instructed not to look at their reports. A surprise recall task demonstrated that rehearsal reduced significantly the detail of dream, but not waking event, reports. It maintained episodic richness for dreams. Furthermore, rehearsed dream and event reports corresponded significantly more closely with original reports than controls. These data indicate that while rehearsal may not increase dream recall over time, it may influence the phenomenology of memories that are subsequently recalled, such that a rehearsed memory is subsequently recalled, rather than the original experience. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Dreams of female university students: Content analysis and the relationship to discovery via the Ullman method.

This study extended the research on the dreams of students by examining the actual content of female students' dreams and to what extent the content related to discovery via the Ullman method. Further analyses were conducted to examine what content categories significantly predicted discovery. Participants were 56 female undergraduate students who provided a dream and participated in the Ullman method of group interpretation. Dream content was analyzed via the Hall and Van de Castle method of content analysis. Many significant correlations were observed among dream content categories, discovery categories, and dream content and discovery categories together. Findings were representative of the sample being examined and provided evidence of the continuity hypothesis. Results both support and extend previous research on the dreams of students. Furthermore, specific categories of dream content were found to significantly predict discovery categories. Limitations and future directions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Content Analysis of German Students' Dreams: Comparison to American Findings

Studies have demonstrated that general dream characteristics, such as gender ratio and familiarity of dream characters, frequency and type of social interactions and settings, and gender differences (e.g., heightened physical aggression in men's dreams), are very stable over time and across different populations. The present study included 537 dreams of 106 women and 39 men (German students). The results confirmed earlier findings regarding the stability of general dream characteristics and gender differences. Only the gender difference regarding the gender ratio of dream characters has not been replicated; this finding might be explained by the relationship status (single vs. stable partnership) of the dreamers. The comparison of large dream samples may shed light on the similarities and differences between the inner worlds of people of different countries and cultures.     

Stereotypical Gender-Based Emotions Are Not Detectable in Dream Reports

This study reports on the number of feelings evoked in men and women by their dream characters as well as on the relative frequency of different kinds of feelings. Thirty-five subjects recorded 320 dreams over a two-week period, submitted dream reports and a dream log of all characters that appeared in their dreams as well as any feelings involving the characters. We found that feelings were pervasive in dreams and that they were evoked by over 80% of a subject's dream characters. Further, negative and positive emotions were balanced for both men and women. We found no significant differences in the number or in the profile of feelings in men and women's dreams. The reasons for this are discussed in terms of a continuity hypothesis across dream and wake states or, on the contrary, that feelings expressed in dreams may be independent of learned gender differences.     

Perceived change in the affect associated with dreams: The fading affect bias and its moderators.

Eighty-two undergraduate participants kept dream diaries for a month. Five dreams were randomly selected from each diary and were returned to participants. They rated the affect produced by the dream at its occurrence and at its recall, as well as a number of other characteristics of the dream and characteristics of the context in which the dream occurred. Results revealed that, like memories for real autobiographical events, the negative affect associated with dreams generally faded faster than the positive affect associated with dreams (a Fading Affect Bias, or FAB). The data also showed that the FAB did not occur for: (a) dreams that were remembered to contain information that dreamers believed came true at a later date, (b) dreamers who had reportedly taken recreational drugs prior to their dream, (c) dreams remembered as lacking sound, and (d) dreams remembered as very quiet. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of session process and outcome in the Hill dream model: Contributions of client characteristics and the process of the three stages.

Forty-two therapists trained in the C. E. Hill dream model (1996, 2004a) conducted single dream sessions with 157 volunteer clients. Clients who profited most from dream sessions had poor initial functioning on the problem reflected in the dream, positive attitudes toward dreams, salient dreams, low initial insight into the dream, and poor initial action ideas related to the dream. When initial stages of the session were evaluated positively, later stages were also evaluated positively. Process (therapist competence/adherence and client involvement) was positively related to session outcome. Perspective also influenced the findings, such that clients', therapists', and judges' perceptions of process related to their own, but not others', evaluations of process and session outcome. Implications of findings for dream work and research are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Dreams of Blind Men and Women: A Replication and Extension of Previous Findings

Drawing on a sample of 372 dreams from 15 blind adults, we present two separate analyses that replicate and extend findings from previous studies. The first analysis employed DreamSearch, a software program designed for use with dream narratives, to examine the appearance of the five sensory modalities. It revealed that those blind since birth or very early childhood had (1) no visual imagery and (2) a very high percentage of gustatory, olfactory, and tactual sensory references. The second analysis found that both male and female participants differed from their sighted counterparts in the same ways on several Hall and Van de Castle (1966) coding categories, including a high percentage of locomotion/transportation dreams that contained at least one dreamer-involved misfortune. The findings on sensory references and dreamer-involved misfortunes in locomotion/transportation dreams are interpreted as evidence for the continuity between dream content and waking cognition.