Threat Simulation Theory Research Articles

Dreaming of being chased reflects waking-life experiences related to negative relationships with others metaphorically.

It has long been argued that there are dream metaphors which express waking-life experiences indirectly. Most of empirical evidence concerning this topic was in a qualitative way, while few studies explored the topic in a quantitative way. Under this background, we investigated whether dreaming of the typical theme 'being chased or pursued' was a metaphorical expression for waking-life experiences related to 'negative relationships with others'. One hundred and sixty participants reported their waking-life experiences and dreams for a single day. Following this, two external judges rated whether there were any elements related to 'negative relationships with others' in both waking-life experiences and dreams. In addition, the judges assessed if there was any content related to 'being chased or pursued' in both waking-life experiences and dreams. The frequency of dreaming of 'negative relationships with others' was higher than the frequency of the same topic in waking-life experiences, which in turn was higher than the frequency of typical theme dreaming of 'being chased or pursued'. In addition, 'negative relationships with others' in waking-life experiences were correlated with both dreaming of 'being chased or pursued', and 'negative relationships with others' in dreams. These results suggested that the typical theme 'being chased or pursued' in dreams may represent some waking-life experiences metaphorically. In addition, the results support the threat simulation theory of dreaming, which suggests that threatening events in waking life increase the possibility of threatening events in dreams.

Imagery of ritual actions in religious dreaming: steps toward a theory and method of the cognition of dreamt ritual interaction

ABSTRACT The research literature on religious dreaming demonstrates the commonness of supernatural agent (SA) imagery, as well as various ritualistic and divinatory uses of dream content in the waking state. Less well mapped is the related domain of dream imagery about rituals (DIR). This article aims to provide a survey and analysis of DIR items and interactions in line with dream and ritual theories, with case illustrations from dream reports based on ethnographic fieldwork among Hindus in Nepal. The analysis relies on an understanding of “ritual” based on their assumed “obvious aspects” and traits, and on theoretical assumptions drawn from cognitive and evolutionary accounts of ritualization in relation to prominent strands in dream research such as threat simulation theory, and social simulation theory. The aim is to develop a novel strategy for exploring imagined ritual traits in dreaming. This undertaking contributes to the methodology and theoretical understanding of religious dream cognition.

Differentiating dreaming and waking reports with automatic text analysis and Support Vector Machines

We analyzed similarities and differences between dream and waking reports in a collection by Kahan and Sullivan (2012). We compared word frequencies in the reports using the automatic text analysis software, Linguistic Inquiry and Word Count (LIWC). Social words were more frequent in dream than waking reports, support for Social Simulation Theory. Positive emotion words were less frequent in dream than waking reports, support for Threat Simulation theory. Amount of cognition was the same in dream and waking reports, i. e., the number of words in the summary category “Cognitive Processes” was not significantly different. But specific categories of cognitive words differed in frequency. We also applied a machine learning technique to dream research and built a support vector machine to achieve binary characteristics detection (here, whether a report is about waking or dream) based on LIWC word counts. Performance metrics for the support vector machine were high.

Presleep Ruminating on Intrusive Thoughts Increased the Possibility of Dreaming of Threatening Events.

This study investigated whether ruminating on an intrusive thought before sleeping led to an increased likelihood of dreaming of threatening events. One hundred and forty-six participants were randomly assigned to a rumination condition (a rumination on an intrusive thought for 5 min before sleeping; N = 73) and a control condition (think about anything for 5 min before sleeping; N = 73). Participants completed a dream diary upon waking. The result showed that presleep ruminating on an intrusive thought increased the frequency of both threatening dreams and negative emotions in dreams. In addition, dreams with threatening events were more emotional and negative than dreams without threatening events. These results may support the threat simulation theory of dreaming. In addition, these results may give some insight into a mathematical model for the continuity hypothesis of dreaming.

The Holocaust as a Lifelong Nightmare: Posttraumatic Symptoms and Dream Content in Polish Auschwitz Survivors 30 Years After World War II

AbstractPosttraumatic symptoms, including nightmares, are more prevalent in World War II survivors than in the general population, but how war experiences have affected subsequent dream content in specific survivor populations remains less explored. In the present study, we used self-reports collected in 1973 from Polish Auschwitz survivors (N = 150; 45 women) to investigate the prevalence of posttraumatic symptoms, classified according to the DSM-5 diagnostic criteria for posttraumatic stress disorder (PTSD). Furthermore, we classified main themes, central emotions, and threatening events in the dreams (N = 632) of the survivors, comparing dreams recalled from before, during, and after the war. Of the respondents, 12.7% described experiencing all diagnostic criteria for PTSD. War-related themes were less common in dreams dreamt before than during the war but were most common after the war. Themes related to family and freedom were most likely to appear in dreams dreamt during than before or after the war. The most often occurring emotion was fear, and dreams from after the war were likely to contain more negative and less positive emotions than dreams dreamt during the war. The likelihoods of reporting threatening events and threats involving aggression were higher in dreams dreamt during than before the war and in dreams dreamt after than during the war. In conclusion, PTSD symptoms were common in Polish Auschwitz survivors 30 years after World War II, and the themes, emotions, and threatening events in their dreams seem to reflect lifelong posttraumatic dreaming. We interpret the results as lending support for the threat simulation theory of dreaming.

The threat simulation in nightmares—Frequency and characteristics of dream threats in frequent nightmare dreamers.

According to the threat simulation theory, the function of dreams is to rehearse threatening situations, which served an evolutionary advantage for our ancestors. Furthermore, the exposure to waking life threats is thus supposed to lead to an increased occurrence or quality of dream threats. Aims of

Autobiographical memory sources of threats in dreams.

Temporal sources of dream threats were examined through the paradigm of the Threat Simulation Theory. Two groups of young adults (18-24 years old), who did not experience severe threatening events in the year preceding their dream and reported a dream either with or without threats, were included. Participants (N = 119) kept a log of daily activities and a dream diary, indicating whether dream components referred to past experiences. The occurrence of oneiric threats correlated with the reporting of threats in the daily logs, their average severity, and the stress level experienced the day preceding the dream. The group whose dreams contained threats had significantly more references to temporal categories beyond one year than the group with dreams without threats. Our findings suggest that in the absence of recent highly negative emotional experiences, the threat simulation system selects memory traces of threatening events experienced in the past.

Pre-sleep and post-sleep mood as a complementary evaluation of emotionally impactful dreams

Impactful dreams are reported by the dreamer to have an effect on their waking mood. However, the time course relationship of negative and positive impactful dreams with pre-sleep and post-sleep mood has not been examined closely. A total of 32 participants (21 females) reported one dream self-rated as either very or extremely emotionally impactful and one dream self-rated as not at all emotionally impactful (mundane dream), totalling 64 dreams. Participants completed a dream diary as well as pre-sleep, dream, and post-sleep mood checklists. They also completed rating scales of the impact of their dreams. The Hall & Van de Castle method was used for dream coding and analysis. A dream containing more positive than negative emotions was classified as positively impactful and vice versa. The 2 x 3 analysis of variance demonstrated a significant difference between mundane dreams and both negative and positive impactful dreams. Overall, negative impactful dreams were associated with higher negative mood levels at pre-sleep, in dream, and at post-sleep, compared to mundane dreams. Conversely, positive impactful dreams were associated with more positive mood levels during the dream and at post-sleep, but not at pre-sleep. Correlational analyses demonstrated that in negative impactful dreams, negative dream mood strongly correlated with negative post-sleep mood. Similarly, in positive impactful dreams, positive dream mood strongly correlated with positive post-sleep mood. However, pre-sleep and dream mood, whether positive or negative, did not significantly correlate. Additionally, there was a significant correlation between pre-sleep and post-sleep positive mood in positive impactful dreams and mundane dreams. These results confirm that dream mood and post-sleep mood are positively related, further suggesting a potential effect on post-sleep mood. The absence of a relationship between pre-sleep and dream mood undermines the continuity theory as well as modern dream function theories for emotions. The threat simulation theory is also used to interpret results.

Threats in dreams, emotions and the severity of threatening experiences in waking

One of the prepositions of the Threat Simulation Theory (TST) suggests that the experience of threatening events in waking life would be associated with the experience of oneiric threats, which is consistent with the Continuity hypothesis. Following on that proposition, dream diaries and daily event diaries of the day preceding the dreams were collected from 40 female and 40 male undergraduate students who rated the intensity of anger and fear experienced during the day and in the course of their dreams. The severity and frequency of threatening events in both conditions was evaluated by two independent judges on a scale developed on the basis of the severity component of Revonsuo’s Dream Threat Scale. There were significant correlations between the severity of threatening day events and the severity of threats in dream diaries (r(80) = .22, p = .048), and between the frequency of daytime threats and dream threats (r(80) = .41, p = .001). There were also significant correlations between pre-sleep anger and anger in dreams (r(80) = .39, p = .01, and between fear before bedtime and the severity of dream threats (r(80) = .33, p =.003). In addition, different gender-specific relationships emerged, coincident with the consistently observed predominance of negative emotions in women’s dreams. These findings provide some support for both the Threat Stimulation Theory and the Continuity hypothesis. Further exploration over a longer time frame is required to better understand the relationship between these emotions experienced in waking and dreams.

Dreams of Canadian Students

A total of 600 dream reports were collected from 300 Canadian university students, 150 female and 150 male, and their content analyzed with the Hall and Van de Castle (1966) system of categories. The main dream content categories were characters, aggressive and friendly interactions, positive and negative emotions, and dream outcomes. The main purpose of the analysis was to provide normative data for a large sample of young Canadians to determine (a) whether negative elements prevail over positive ones, as assumed by the threat simulation theory and (b) whether dream gender differences are consistent with differences in waking life, in accordance with the continuity hypothesis. Overall, findings support both theories. The final objective was to compare the Canadian data, relative to gender differences, with normative data established in 1966 with the original American sample. Findings for males and females and gender differences remain consistent with the American normative data for most categories despite a 50 years interval. Similarities in Canadian and American dream content reflect similarities between the respective cultures. They also attest to fundamental structural dimensions of dream content that transcend cultures. Other types of content analysis relative to themes, for instance, might be appropriate to highlight cultural differences.

Threats in dreams: Are they related to waking-life?

According to the Threat Simulation Theory (TST) dreaming has developed and was maintained during evolution because its function of rehearsing threats is essential for survival. The present study analyzed 1612 diary dreams reported by 425 participants (mainly psychology students). The study results indicate that threats play an important role in dreams and, thus, support the idea that dreaming might have a function of rehearsing problematic or threatening situations. Comparing the present results to previous findings shows a considerably large variability regarding the number of threats per dream, the proportion of minor threats, and the reality of threats. As neuroticism and openness to experience were related to the number of threats per dreams, future research should investigate inter-individual differences in waking life which might help explain the variability regarding the dream threat characteristics.

The content of recurrent dreams in young adolescents.

Studies on children's recurrent dreams have been largely anecdotal and based on adults' recollections of dreams experienced during childhood. We collected 102 reports of recurrent dreams from a sample of young adolescents aged between 11 and 15years and scored the narratives using a range of content measures, including in relation to the threat simulation theory (TST) of dreaming. The most frequently reported themes involved confrontations with monsters or animals, followed by physical aggressions, falling and being chased. Recurrent dreams were more likely to include negative content elements than positive elements. Only half of the recurrent dreams contained threatening elements and their analysis provided mixed support for the TST. Differences between the content of recurrent dreams reported by young adolescent versus adults are discussed as are possible sex effects and key issues that remain to be addressed by future research.

Approach/avoidance in dreams

The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams.

Dreaming in religion and pilgrimage: cognitive, evolutionary and cultural perspectives

Dreams are a universal human experience and they form cultural themes in folk traditions and religious rituals, such as pilgrimages and dream incubation. Dreams and dream beliefs are important since they contain representations of interacting supernatural agents that have full access to information of strategic importance to humans. The relevance of dreams often relates to the dreamers' concerns about the future and about health, and in this sense they show similarity with divination and oracles. This article suggests that religious dreaming is underpinned by an evolved system of threat simulation that is activated in dreaming processes; this is associated with a proclivity to evoke agent concepts and to use counterintuitive representations in cultural communication. It is argued that the use of a ‘hypersensitive agency detection device’ draws upon emotionally laden threat simulation in dreaming that makes reference to counterintuitive supernatural agents that are particularly relevant. This suggests that recalling religious dreams and the cultural transmission of dream reports, narratives and interpretations rely on representations of agents in general and the salience of counterintuitive agents in particular. Furthermore, the explanatory adequacy of ‘threat simulation theory’ is related to non-apprehensive religious dreams and ‘social simulation theory’. These discussions lead on to ethnographic descriptions of the connections between ‘supernaturalism’, pilgrimage, dream beliefs and dream incubation rituals in Nepalese Himalaya and Indian Bengal.

In the midnight hour: Cancer and nightmares. A review of theories and interventions in psycho-oncology

The purposes of this study were: (1) to explore cancer patients' complaints of poor sleep, which often involve a combination of somatic symptoms and nightmares; and (2) to understand these sleep disturbances in the light of modern dream theories and intervention modalities. The literature search originated with several major articles (Revonsuo, 2000; Krakow & Zadra, 2006; Hobson, 2009) which then opened up the search through their references. We also used the database PubMed, and employed the following key words: cancer, nightmares/dreams, sleep disturbances, and dream theory. The literature search covered the interval between 1900 (Freud, 1900) and 2009. Our criteria for selecting studies included the most recent major review articles on the neuroscience of sleep and dreams; articles reviewing sleep disturbances in cancer patients and relevant treatments; and articles reviewing interventions for traumatic dreams. Approximately 30 articles were deemed worthy of inclusion. Thirty article/books/chapters met the criteria for relevance related to key theories and clinical interventions related to nightmares and traumatic dreams of cancer patients. Key concepts involve threat simulation theory and imagery rehearsal therapy in regard to theoretical and interventional paradigms significantly generalizable to cancer patients. The dream material included in this article presents patients' attempts to deal with complex threats such as intense dependency/ loss of self-sufficiency, disfigurement, and death. This is especially true with regard to the doctor-patient relationship at all stages of the illness and disease. Imagery rehearsal can facilitate empowerment in light of highly threatening and conflictual cancer-related dreams in which the patient feels helpless and victimized. This review offers a new lens on current dream theories and understanding of sleep disturbance in cancer patients as well as their familes and medical caregivers. Modern theories lead to opportunities for intervention that can both relieve symptoms and improve communication between medical caregivers and patients and families.

The threat simulation theory in light of recent empirical evidence: A review

The recently proposed threat simulation theory (TST) states that dreaming about threatening events has a biological function. In the past few years, the TST has led to several dream content analysis studies that empirically test the theory. The predictions of the TST have been investigated mainly with a new content analysis system, the Dream Threat Scale (DTS), a method developed for identifying and classifying threatening events in dreams. In this article we review the studies that have tested the TST with the DTS. We summarize and reevaluate the results based on the dreams of Finnish and Swedish university students, traumatized and nontraumatized Kurdish, Palestinian, and Finnish children, and special dream samples, namely recurrent dreams and nightmares collected from Canadian participants. We sum up other recent research that has relevance for the TST and discuss the extent to which empirical evidence supports or conflicts with the TST. New evidence and new direct tests of the predictions of the TST yield strong support for the theory, and the TST's strengths seem to outweigh its weaknesses.

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.

Shooting the messenger won’t change the news

Malcolm-Smith, Solms, Turnbull and Tredoux [Malcolm-Smith, S., Solms, M., Turnbull, O., & Tredoux, C. (2008). Threat in dreams: An adaptation? Consciousness and Cognition, 17, 1281–1291.] conducted a rigorous study that sampled two populations differentially exposed to threat in real life, and found that critical predictions from the Threat Simulation Theory of dreams [Revonsuo, A. (2000a). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23, 877-901.; Revonsuo, A. (2000b). Did ancestral humans dream for their lives? Behavioral and Brain Sciences, 23, 1063–1082.] were not supported. Specifically, we found no evidence of increased realistic threats to physical survival or enhanced threat avoidance in the dreams of those from the exposed population. Revonsuo and Valli’s [Revonsuo, A., & Valli, K. (2008). How to test the threat simulation theory. Consciousness and Cognition, 17, 1292-1296.] commentary on our study argues that the methods we used are so flawed as to render the results meaningless. In this response article, we address the criticisms raised in their commentary.

How to test the threat-simulation theory

Malcolm-Smith, Solms, Turnbull and Tredoux [Malcolm-Smith, S., Solms, M.,Turnbull, O., & Tredoux, C. (2008). Threat in dreams: An adaptation? Consciousness and Cognition, 17, 1281–1291.] have made an attempt to test the Threat-Simulation Theory (TST), a theory offering an evolutionary psychological explanation for the function of dreaming [Revonsuo, A. (2000a). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23(6), 877–901]. Malcolm-Smith et al. argue that empirical evidence from their own study as well as from some other studies in the literature does not support the main predictions of the TST: that threatening events are frequent and overrepresented in dreams, that exposure to real threats activates the threat-simulation system, and that dream threats contain realistic rehearsals of threat avoidance responses. Other studies, including our own, have come up with results and conclusions that are in conflict with those of Malcolm-Smith et al. In this commentary, we provide an analysis of the sources of these disagreements, and their implications to the TST. Much of the disagreement seems to stem from differing interpretations of the theory and, consequently, of differing methods to test it.

Dreams are more negative than real life: Implications for the function of dreaming

Dream content studies have revealed that dream experiences are negatively biased; negative dream contents are more frequent than corresponding positive dream contents. It is unclear, however, whether the bias is real or due to biased sampling, i.e., selective memory for intense negative emotions. The threat simulation theory (TST) claims that the negativity bias is real and reflects the evolved biological function of dreaming. In the present study, we tested the hypothesis of the TST that threatening events are overrepresented in dreams, i.e., more frequent and more severe in dreams than in real life. To control for biased sampling, we used as a baseline the corresponding negative events in real life rather than the corresponding positive events in dreams. We collected dream reports (N=419) and daily event logs (N=490) from 39 university students during a two-week period, and interviewed them about real threat experiences retrievable from autobiographical memory (N=714). Threat experiences proved to be much more frequent and severe in dreams than in real life, and Current Dream Threats more closely resembled Past than Current Real Threats. We conclude that the TST's predictions hold, and that the negativity bias is real.