Personality and Dream Recall Frequency: Still Further Negative Findings

In order to investigate the relationship between dream recall frequency and personality, 116 college undergraduates kept a dream log for 21 consecutive nights and completed self-report measures assessing fantasy-proneness, psychological absorption, and imaginative involvement. Consistent with most previous literature in this area, with one exception, there were no significant associations found between dream recall and the personality measures. The one exception to this pattern was for fantasy proneness and this correlation was of a small magnitude and only obtained for women. We conclude that dream recall frequency is largely independent from stable personality traits and can better be understood in terms of expectancy and attitudinal factors.     

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.     

Personality and Dream Recall Frequency: Further Negative Findings

On the basis of previous findings of dream recall frequency being associated with thin boundariness and sensitivity we assessed the association between DRF and variables that appear related to these two measures. Data from 93 participants (47 males, 46 females, mean age 21.3 yrs., SD = 3.5) show that dream recall frequency (DRF) correlates marginally with neuroticism (r = .20) and interrogative suggestibility (r = .21), the latter result indicating that DRF obtained by questionnaire may be subject to demand bias. DRF had very low correlations with various other personality variables (need for cognition, personal locus of control, hypochondriasis, morningness-eveningness), and with narrative memory, confabulation of narrative memory, and habitual sleep length. DRF correlated positively with POMS elated (-depressed) for males (r = .31) but negatively for females (r = –.19), this significant difference in correlations may be due to sex differences in DRF in response to stress. The frequent findings of small or nonsignificant correlations between DRF and personality are discussed in terms of similar low correlations in personality psychology, but we conclude that DRF is usually sampled adequately, and that the results of no simple relationship with personality (except boundariness, creativity, and positive attitude towards dreams) are therefore robust and may indicate that dream recall is mainly determined physiologically.     

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.     

Definitions of Dream: A Paradigm for Comparing Field Descriptive Specific Studies of Dream

A single definition for dreaming is most likely impossible given the wide spectrum of fields engaged in the study of dreaming, and the diversity in currently applied definitions. Many studies do not specify a definition, yet results are likely to be comparable only when comparable definitions of the topic are used. The alternative is to develop a classification system organizing the multiplicity of definitions for dream. A dream should not be exclusively defined as a non-conscious electrophysiologic state. Dreaming is, at least in part, a mental experience that can be described during waking consciousness. Definitions for dreaming should be utilized in research and discussion which address the various axes which define dreaming: Wake/sleep, Recall, and Content.     

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.     

Conscious experiences and high-density EEG patterns predicting subjective sleep depth

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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.     

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.     

Boundary Questionnaire Results in the Mentally Healthy Elderly

The Hartmann Boundary Questionnaire was administered twice, with six months in between, to 61 Swiss subjects over 60 years of age taking part in an investigation into the effects of dream-telling on five variables: well-being, sleep quality, sleep duration, dream recall and dream tone. In addition, dream epoch, i.e., the age of life of the dreamer as perceived in the dream, was recorded for those who told dreams. In addition to this study group in which the members told dreams there were two control groups. Those in the first control group were asked about well-being and sleep quality but not about dreams or dreaming, while those in the second control group were additionally asked how many dreams they had retained, how frequently they had occurred and about the dream tone (pleasant/unpleasant). All study participants were given the Hartmann Boundary Questionnaire at the beginning (pre-test) and again at the end of the six month study period (post-test). The retest reliability was high (r = 0.872 for the whole sample). We report here the relationships obtained between the questionnaire scores and age, group membership, gender and the number of dreams that were retained over a 26 week testing period. No significant correlations were found for age, group membership or dream recall. There was, however, a small, significant boundary score difference between women and men for the pre-test, indicating thinner boundaries for women, but this difference was no longer significant in the post-test.     

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)     

基于Flexible ICA的睡眠EEG及EOG中心电伪差的消除

提出了一种采用自适应非线性函数的ICA学习算法,Flexible ICA算法,并将其应用于睡眠EEG自动分期的前期预处理中,用于消除采集到的各通道信号中的心电伪差.实验结果证明,Flexible ICA算法能够快速有效的消除各通道的心电伪差,为后期的睡眠EEG自动分期打下了良好的基础.     

EEG Correlates of Anxiety and Emotional Stability in Adult Healthy Subjects

We studied peculiarities of the spectral characteristics of EEG in 111 healthy adult subjects of both sexes. The levels of situative anxiety (anxiety state) and personal anxiety were estimated using the Spielberger–Khanin test system. To estimate anxiety-related properties of the personality, Cattel’s technique 16 PF (form А) was used. Estimates of situative anxiety demonstrated only two cases of positive correlation with the spectral power density (SPD) of EEG rhythms (SPDs of the beta2 rhythm in the right-hemisphere temporal and occipital regions; recording with the eyes open). Estimates of personal anxiety positively correlated with the SPDs of the beta1 and (especially) beta2 EEG rhythms. Under conditions with the eyes open, the number of significant correlations was greater, and correlations themselves were tighter than with the eyes closed. The closest correlations of the estimates of personal anxiety with the SPDs of the beta rhythm were found in frontal and central leads of both hemispheres and in parietal and occipital loci of the right hemisphere. Only a single case of correlation of the alpha rhythm SPD with personal anxiety (negative correlation, a parietal lead in the left hemisphere) was found. At the same time, rather numerous correlations of the alpha rhythm expression with an index congeneric to anxiety, the C factor by the Cattel’s questionnaire (emotional stability/instability), were found. Thus, the intense beta EEG rhythm can be considered an electrographic correlate of high situative and personal anxieties. At the same time, the alpha rhythm power correlates with the emotional stability of the individual. We suppose that persons with a well-developed alpha rhythm are characterized by active and stable functioning of the cerebral dopaminergic system; this simultaneously serves as a pre-requisite of high emotional stability and social adaptability.     

Topographical EEG Mapping in a Case of Recurrent Sleep Terrors

Sleep terrors are characterized by marked CNS arousal and typically occur during stage 3-4 sleep within the first NREM cycle. Studies of the EEG during sleep terrors suggest that delta power and synchrony in the EEG may be important physiological markers of sleep terror presence and intensity. An EEG mapping study was undertaken with a single participant who experienced three sleep terror episodes in the laboratory. A one-minute section of EEG was sampled immediately prior to the onset of each of the three sleep terrors. Similar EEG sections were taken from 10 healthy sex- and age-matched controls. The sleep tenors and control (normative) data were then compared topographically with z-scores (z-mapping). The z-maps indicated that all three sleep terrors contained more total and delta power in central and frontal areas than the control EEG sections. Moreover, relative delta power in these areas for the three sleep terrors was proportional to the subjective intensity of the episode. Although this pre-arousal EEG pattern may be related to ongoing slow-wave sleep mentation that may sometimes trigger sleep terror episodes, its functional significance remains an open question. The results demonstrate the utility of EEG mapping for the quantification of brain activation during sleep terror attacks and suggest that discrete activity profiles are identifiable for different types of dreaming-related arousal.     

The role of mood congruency memory effects in dream recall: A pilot study.

A methodological issue in research relating daytime mood to dream content is the question of whether mood congruency effects—that is, recalling more negative events if the current mood is more negative—also play a role in the dream recall process. This study adopted an indirect approach by testing the hypothesis that interindividual differences in mood congruency effects in a memory task carried out in the daytime correlate with mood congruency effects in dream recall (recalling more negative dream emotions, as one would predict on the basis of the current stress level or overall mood state). The findings, however, did not support the hypothesis of mood congruency effects and, thus, rule out that the findings regarding the continuity hypothesis of dreaming are biased by selective recall. Studies with different methodological approaches are necessary to validate this study’s findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender Differences in the Content Analysis of 240 Dream Reports from Brazilian Participants in Dream Seminars

This study asked the question, “Are there significant content differences between male and female dream reports obtained in dream seminars conducted in Brazil?” Each of the 240 (137 female, 103 male) research participants volunteered recent dream reports (one per person) during dream seminars that he or she attended between 1990 and 1998. Dreams were scored according to Hall-Van de Castle criteria. Comparative Cohen h-statistics revealed several gender differences. Further study is recommended because the dream reports did not represent Brazil's social-economic diversity, and may not have been characteristic of the totality of participants' dream lives.     

Reliability and stability of dream recall frequency.

Although a large number of studies investigating factors affecting dream recall frequency (DRF) have been carried out, research investigating the reliability and stability of DRF is scarce. Dream diaries of 196 participants kept over at least 28 days were analyzed. The results of the present study indicate that a time period of 2 weeks was sufficient to obtain reliable measurements of interindividual differences in DRF. Despite the high day-to-day fluctuations of dream recall, the stability of this variable was very high. Studies that investigate the stability of DRF by means of other methodological approaches (e.g., questionnaire scales, laboratory awakenings) and over longer time periods (e.g., 1 year) should be carried out to complement the present findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Predictors of Outcome of Dream Interpretation Sessions: Volunteer Client Characteristics, Dream Characteristics, and Type of Interpretation

105 volunteer clients completed single sessions of dream interpretation using the Hill (1996) model, with half randomly assigned to waking life interpretation and the other half to parts of self interpretation in the insight stage of the Hill model. No differences were found between waking life and parts of self interpretations, suggesting that therapists can use either type of dream interpretation. Volunteer clients who had positive attitudes toward dreams and presented pleasant dreams had better session outcome; in addition, volunteer clients who had pleasant dreams gained more insight into their dreams. Results suggest that therapists doing single sessions of dream interpretation need to be cautious about working with dreams when volunteer clients have negative attitudes toward dreams and present unpleasant dreams.