Digital dream analysis: A revised method

This article demonstrates the use of a digital word search method designed to provide greater accuracy, objectivity, and speed in the study of dreams. A revised template of 40 word search categories, built into the website of the Sleep and Dream Database (SDDb), is applied to four “classic” sets of dreams: The male and female “Norm” dreams of Hall and Van de Castle (1966), the “Engine Man” dreams discussed by Hobson (1988), and the “Barb Sanders Baseline 250” dreams examined by Domhoff (2003). A word search analysis of these original dream reports shows that a digital approach can accurately identify many of the same distinctive patterns of content found by previous investigators using much more laborious and time-consuming methods. The results of this study emphasize the compatibility of word search technologies with traditional approaches to dream content analysis.     

Similarities and differences in dream content at the cross-cultural, gender, and individual levels

The similarities and differences in dream content at the cross-cultural, gender, and individual levels provide one starting point for carrying out studies that attempt to discover correspondences between dream content and various types of waking cognition. Hobson and Kahn’s (Hobson, J. A., & Kahn, D. (2007). Dream content: Individual and generic aspects. Consciousness and Cognition, 16, 850–858.) conclusion that dream content may be more generic than most researchers realize, and that individual differences are less salient than usually thought, provides the occasion for a review of findings based on the Hall and Van de Castle (Hall, C., & Van de Castle, R. (1966). The content analysis of dreams. New York: Appleton-Century-Crofts.) coding system for the study of dream content. Then new findings based on a computationally intensive randomization strategy are presented to show the minimum sample sizes needed to detect gender and individual differences in dream content. Generally speaking, sample sizes of 100–125 dream reports are needed because most dream elements appear in less than 50% of dream reports and the magnitude of the differences usually is not large.     

Emotions in Diary Dreams

Even though various investigations found a preponderance of negative emotions in dreams, the conclusion that human dream life is, in general, negatively toned is limited by several methodological issues. The present study made use of three different approaches to measure dream emotions: dream intensity rated by the dreamer, intensity rated by a judge, and scoring of explicitly mentioned emotions (Hall & Van de Castle, 1966). Results indicate that only in the case of external raters' estimates do negative emotions outweigh the positive ones; but in the case of self-ratings (i.e., those made by the dreamer himself/herself), the ratio was balanced. Analyses showed that this is mainly due to the underestimation of positive emotions in the external ratings. Additionally, a positive correlation was found between the intensity of dream emotions and dream recall frequency, whereas gender differences were nonsignificant as regards the emotional tone of diary dreams.     

Studying dream content using the archive and search engine on DreamBank.net

This paper shows how the dream archive and search engine on DreamBank.net, a Web site containing over 22,000 dream reports, can be used to generate new findings on dream content, some of which raise interesting questions about the relationship between dreaming and various forms of waking thought. It begins with studies that draw dream reports from DreamBank.net for studies of social networks in dreams, and then demonstrates the usefulness of the search engine by employing word strings relating to religious and sexual elements. Examples from two lengthy individual dream series are used to show how the dreams of one person can be studied for characters, activities, and emotions. A final example shows that accurate inferences about a person’s religious beliefs can be made on the basis of reading through dreams retrieved with a few keywords. The overall findings are similar to those in studies using traditional forms of content analysis.     

Automatic gender detection of dream reports: A promising approach

A computer program was developed in an attempt to differentiate the dreams of males from females. Hypothesized gender predictors were based on previous literature concerning both dream content and written language features. Dream reports from home-collected dream diaries of 100 male (144 dreams) and 100 female (144 dreams) adolescent Anglophones were matched for equal length. They were first scored with the Hall and Van de Castle (HVDC) scales and quantified using DreamSAT. Two male and two female undergraduate students were asked to read all dreams and predict the dreamer’s gender. They averaged a pairwise percent correct gender prediction of 75.8% (κ = 0.516), while the Automatic Analysis showed that the computer program’s accuracy was 74.5% (κ = 0.492), both of which were higher than chance of 50% (κ = 0.00). The prediction levels were maintained when dreams containing obvious gender identifiers were eliminated and integration of HVDC scales did not improve prediction.     

Effects of Gender-Role Self-Discrepancy on Depressed Mood

Gender and gender role comparisons of manifestdream content were investigated by analyzing the dreamsof male and female college students, 16% of whom wereethnic minorities. Dreams were coded using the C. S. Hall and R. Van de Castle [(1966) TheContent Analysis of Dreams, New York: Appleton] codingsystem; participants also completed the Bem Sex-RoleInventory [(S. L. Bem, 1981) Bem Sex-Role Inventory Professional Manual, Palo Alto, CA: ConsultingPsychologists Press]. Gender × Gender Rolemultivariate analyses of covariance, with dream lengthas the covariate, indicated greater gender similaritythan in previous decades. Gender role differencesdid emerge for content previously viewed asdistinguishing men's dreams: a masculine gender role wasassociated with a higher frequency of weapons,unfamiliar characters, male characters, aggressiveinteractions, and failure outcomes. Findings areinterpreted in terms of changing patterns of gender rolesocialization, the convergence of male and female roles, and the continuity of conscious and unconsciouspreoccupations.     

Dreaming and cognition in patients with frontotemporal dysfunction

Individuals with Parkinson’s disease (PD) and temporal lobe epilepsy (TLE) have hallucinations and mild cognitive dysfunction. The objective of this work was to study dreams in PD and TLE patients using a common functional model of dream production involving the limbic and paralimbic structures.Dreams were characterised in early-stage PD (19 males) and TLE patients (52) with dream diaries classified by the Hall van de Castle system and were compared with matched controls.In PD, there were significant differences between patients’ dreams and those of controls: animals, physical aggression, and a befriender were more common in patients, and aggressor and bodily misfortunes were less common. The dreams of patients with frontal dysfunction showed more aggressive features.TLE patients had lower recall than PD patients and a higher proportion of dreams involving family and familiar settings, lower proportions involving success, and a higher incidence of frontal dysfunction.The dreams of PD and TLE patients share important features.     

The impact of September 11 on dreaming

This study focuses on a set of dreams related to the September 11, 2001 terrorist attacks and their aftermath, using content analysis and cognitive psychology to explore the interweaving of external public catastrophe and internal psychological processes. The study tests several recent claims in contemporary dream research, including the central image theory of Hartmann [Hartmann, E., & Basile, R. (2003). Dream imagery becomes more intense after 9/11/01. Dreaming, 13(2), 61-66; Hartmann, E., & Brezler, T. (2008). A systematic change in dreams after 9/11/01. Sleep, 31(2), 213-218], the media exposure factor postulated by Propper [Propper, R. E., Stickgold, R., Keeley, R., & Christman, S. D. (2007). Is television traumatic? Dreams, stress, and media exposure in the aftermath of September 11, 2001. Psychological Science, 18(4), 334-340], the continuity hypothesis of Domhoff [Domhoff, W. G. (1996). Finding meaning in dreams: A quantitative approach. New York: Plenum], the cognitive and metacognitive approach of Kahan [Kahan, T. L. (2001). Consciousness in dreaming: A metacognitive approach. In K. Bulkeley (Ed.), Dreams: A reader on the religious, cultural, and psychological dimensions of dreaming (pp. 333-360). New York: Palgrave], and the threat simulation theory of Revonsuo [Revonsuo, A. (2000). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23(6), 877-901]. Our findings suggest the terrorist attacks had a tangible impact on the content of many people's dreams, but did not fundamentally alter the cognitive processing features of their dreaming. The 9/11 attacks affected what they dreamed about, but not the way they dreamed.     

Relation between waking sport activities, reading, and dream content in sport students and psychology students

The continuity hypothesis in its general form states that dreams reflect waking life: concerns, thoughts, and experiences (G. W. Domhoff, 1996; M. Schredl, 1999; I. Strauch & B. Meier, 1996). For example, athletes and sport students dream about sports more often than do psychology students, presumably reflecting their engagement in sport activities and sport theory (D. Erlacher & M. Schredl, 2004). In the present study, the authors tested the previously unexamined hypothesis that differences in dream content would directly reflect individuals' differing amounts of waking sport activities. As expected, the amount of time that individuals spent engaged in an activity (sports or reading) was directly related to their percentage of corresponding dreams. Also, individuals reported reading dreams less frequently than they did sport dreams, although reading was more prominent in their waking lives than were sport activities. The findings also indicated that other factors such as emotional involvement and associated worries might be of importance in explaining the relation between waking activities and dream events. Future studies using longitudinal designs would shed more light on this relation and would help derive a more precise formulation of the continuity hypothesis.     

NonREM sleep mentation in chronically-treated persons with schizophrenia

This study examined the laboratory dream content reported by 14 patients with schizophrenia and 15 controls, with a focus on reports obtained from NonREM sleep. Both the controls' and patients' frequency of dream recall following awakenings from NonREM and REM sleep were similar to values reported for healthy participants. Patients' NonREM sleep narratives were shorter than those from controls. When compared to their reports from REM sleep, both groups' NonREM sleep reports included significantly fewer words and reportable items. The controls were more likely to report a subjective feeling of bizarreness for their REM sleep reports as compared to their NonREM sleep reports. This difference was not observed in patients with schizophrenia. Taken together, these findings suggest few differences between the NonREM sleep mentation of patients with schizophrenia and of controls and that sleep stage cognitive style is comparable in both groups, with NonREM sleep reports being more thought-like, less elaborate and bizarre than REM sleep reports.     

Word associations contribute to machine learning in automatic scoring of degree of emotional tones in dream reports

Scientific study of dreams requires the most objective methods to reliably analyze dream content. In this context, artificial intelligence should prove useful for an automatic and non subjective scoring technique. Past research has utilized word search and emotional affiliation methods, to model and automatically match human judges’ scoring of dream report’s negative emotional tone. The current study added word associations to improve the model’s accuracy. Word associations were established using words’ frequency of co-occurrence with their defining words as found in a dictionary and an encyclopedia. It was hypothesized that this addition would facilitate the machine learning model and improve its predictability beyond those of previous models. With a sample of 458 dreams, this model demonstrated an improvement in accuracy from 59% to 63% (kappa = .485) on the negative emotional tone scale, and for the first time reached an accuracy of 77% (kappa = .520) on the positive scale.     

Contrasting off-line segmentation decisions with on-line word segmentation during reading

In two experiments, we investigated the correspondences between off-line word segmentation and on-line segmentation processing during Chinese reading. In Experiment 1, participants were asked to read sentences which contained critical four-character strings, and then, they were required to segment the same sentences into words in a later off-line word segmentation task. For each item, participants were split into 1-word segmenters (who segmented four-character strings as a single word) and 2-word segmenters (who segmented four-character strings as 2 two-character words). Thus, we split participants into two groups (1-word segmenters and 2-word segmenters) according to their off-line segmentation bias. The data analysis showed no reliable group effect on all the measures. In order to avoid the heterogeneity of participants and stimuli in Experiment 1, two groups of participants (1-word segmenters and 2-word segmenters) and three types of critical four-character string (1-word strings, ambiguous strings, and 2-word strings) were identified in a norming study in Experiment 2. Participants were required to read sentences containing these critical strings. There was no reliable group effect in Experiment 2, as was the case in Experiment 1. However, in Experiment 2, participants spent less time and made fewer fixations on 1-word strings compared to ambiguous and 2-word strings. These results indicate that the off-line word segmentation preferences do not necessarily reflect on-line word segmentation processing during Chinese reading and that Chinese readers exhibit flexibility such that word, or multiple constituent, segmentation commitments are made on-line.     

An investigation of the use of nocturnal dream reports as diagnostic indices in the assessment of family problem solving

This study investigated the use of series of nocturnal dream reports to diagnose patterns of family functioning. Five families (twenty one subjects) collected a total of 126 dreams. A Treatment Group consisted of two families undergoing family therapy whilst a Non-Treatment Group, comprising three families, was drawn from a population ranging from severely disturbed to superior family functioning. The manifest content of the dreams was analysed, qualitatively and quantitatively. The presenting problem, case history, therapeutic processes and outcome were unknown to the dream researcher. The family therapist was blind to the dream content and dream analysis. Each family was independently rated by the therapist and the dream researcher. The agreement between the two assessments was highly significant. In addition, the problem areas, family transactions and treatment outcome were correctly identified by the dream researcher. It was concluded that analyses of dream series reflect the problem areas encountered by a family system. Implications for therapeutic strategies are discussed.     

Inflection,frequency, and the word superiority effect

Summary It has been known for nearly 100 years that single words presented tachistoscopically are better recognized than arbitrary letter strings. The present experiments investigate the impact of the morphological structure of words and of word frequency on the word superiority effect. It has been shown that inflected word forms show higher reaction time and error scores in the lexical decision task and higher error scores in the Reicher-Wheeler paradigm. Word frequency also determines lexical decision time. However, no frequency effect in the Reicher-Wheeler paradigm could be found. The results are discussed in the framework of McClelland and Rumelhart's (1981) model of context effects in letter search.This paper is mainly (Experiments I and III) based on the first author's Habilitationsschrift from October, 1982 (cf. Günther 1983a).     

Motivation and affect in REM sleep and the mentation reporting process

Although the emotional and motivational characteristics of dreaming have figured prominently in folk and psychoanalytic conceptions of dream production, emotions have rarely been systematically studied, and motivation, never. Because emotions during sleep lack the somatic components of waking emotions, and they change as the sleeper awakens, their properties are difficult to assess. Recent evidence of limbic system activation during REM sleep suggests a basis in brain architecture for the interaction of motivational and cognitive properties in dreaming. Motivational and emotional content in REM and NREM laboratory mentation reports from 25 participants were compared. Motivational and emotional content was significantly greater in REM than NREM sleep, even after controlling for the greater word count of REM reports.     

Mindless reading revisited: Eye movements during reading and scanning are different

In an extension of a study by Vitu, O’Regan, Inhoff, and Topolski (1995), we compared global and local characteristics of eye movements during (1) reading, (2) the scanning of transformed text (in which each letter was replaced with a z), and (3) visual search. Additionally, we examined eye behavior with respect to specific target words of high or low frequency. Globally, the reading condition led to shorter fixations, longer saccades, and less frequent skipping of target strings than did scanning transformed text. Locally, the manipulation of word frequency affected fixation durations on the target word during reading, but not during visual search or z-string scanning. There were also more refixations on target words in reading than in scanning. Contrary to Vitu et al.’s (1995) findings, our results show that eye movements are not guided by a global strategy and local tactics, but by immediate processing demands.     

Methodological issues in the quantitative analysis of dream content

Reviews measurement approaches applied to dream reports and proposes some methodological cautions that may result in more effective utilization of the dream report in research and assessment. Standardization of dream collection techniques and controls for variability in the length of dream reports are suggested. Further investigation of the intraindividual consistency of dream report measures is seen as necessary for a discussion of their validity. Though there are indications that a variety of dream report measures are potentially valid for psychological assessment, measures based on general dream report characteristics show greater promise than specific content analysis. Research on the differences between normal and disturbed subjects highlights the potential, and the problems, inherent in the use of dream reports as tools of psychological inquiry.     

Analyzing information search patterns to test the use of a two-phased decision strategy

This study compares three procedures, Payne's index, Van Raaij's index and the single Markov model, to test the hypothesis that subjects apply two decision strategies successively in making a choice. The information search patterns were gathered for 72 subjects by means of an information display board. The decision tasks varied in complexity (3, 5, 8 alternatives and 4, 6, 8 attributes). The number of tests which resulted in a significant difference (p < 0.05) were respectively, six out of eighteen t-tests for Payne's index, fourteen out of eighteen t-tests regarding Van Raaij's index, and eight out of nine Chi-square tests for the single Markov model. The theoretical considerations as well as the results suggest that Payne's index is the least sensitive, and that Van Raaij's index, compared to the Markov model, is less sensitive to detect a difference in strategies used.     

Triadic decision making in lexical memory

Word and category recognition was investigated in the context of other stimuli, where the semantic distance relationships among the stimuli were derived from multidimensional scaling. On each trial, three horizontal strings of letters were presented. In the word condition, a positive response was required when the three strings formed three words; in the category condition, a positive response was required when the three strings formed words belonging to the same category. The results indicated that: (a) category decisions take about 150-200 msec longer than do word decisions, (b) word decisions are facilitated by a common categorical membership but semantic distances within the category are relatively unimportant, and (c)within-category semantic distances systematically altered response time for the category condition. It was hypothesized that semantic distance relationships may be sensitized for categorical decisions, but that only large semantic distances function effectively for word decisions.