<p>This study investigates the effects of traumatic experiences on emotional content of dreams. The theoretical framework of the present study is both the threat simulation theory and Hartmann’s theory of dreams as a mechanism for handling emotions after traumatic events. Both theories predict an increase in negative emotions after trauma but assign a different function for this increase. The subjects in this study (N = 16) were regularly writing dream diaries which after the 9/11 attack gave the researchers an unique opportunity to study the exact impact of events on dream content. Each subject’s ten last dreams before 9/11, and ten first dreams after 9/11, were analysed according to the emotional content. The results showed no significant differences in the number or tone of emotions in the before dreams compared to the after dreams. Possibly because none of the subjects experienced the event first hand.</p>

The current dissertation examined gender, cultural, and ontogenetic dimensions in the dreams of Canadians. Normative studies in the United States, Europe, and other countries have documented normative data including gender differences and compared their findings to American data to investigate cultural differences. The purpose of the present study was to extend research of this nature by establishing normative data for Canadians. Furthermore, age differences in dreams have been mostly investigated for females, with only a few studies with males, and have used a variety of methodologies and age ranges. Another objective of this study was to document, for the first time, the ontogenetic pattern of the main dream content categories from adolescence to old age for males and females. The rigorous and detailed dream diary method was used to collect dreams which were analyzed using the Hall and Van de Castle method of content analysis. The first paper consisted of two dreams each from 150 male and female young adult Canadians, ages 18-24, totaling 600 dream reports. Findings provided support for the threat simulation theory as there were more negative than positive themes overall. Furthermore, dream gender differences were consistent with those in waking and the similarity of Canadian and American culture was reflected in dream imagery, supporting the continuity hypothesis of dream formation. The final two papers examined the ontogenetic patterns of dream content for females and males respectively. The second paper consisted of 75 females across 5 age groups from adolescence to old age (12-17, 18-24, 25-39, 40-64, and 65-85) and the third paper consisted of 50 males across the same age groups with the exception of 31 males in the oldest group (65-85). The ontogenetic patterns of dream content from adolescence to old age reflected waking developmental patterns as proposed by social theories, neurobiological research, and recognized features of aging, supporting the continuity hypothesis. In terms of the theoretical implications, this work provides support for the hypothesis of the threat simulation theory pertaining to the prevalence of negative content in dreams. It also provides support for the continuity between waking and dreaming hypothesis of dream formation. Implications of these findings regarding our understanding of the sources of dream formation are described. Finally, limitations and future directions, for research examining the evolution of gender differences across the lifespan, are discussed.

<p>The present study set out to test some of the predictions made by the Threat Simulation Theory, which suggests an evolutionary source of dreaming (Revonsuo, 2000a). The qualitative content and frequency of threatening events in dreams were compared between traumatized Swedish subjects with experience of the tsunami-disaster in Southeast Asia in 2004 with Swedish subjects with no traumatic experiences. Only a few of the hypotheses were supported by the results. The results and unsupported hypotheses are discussed with focus on the Threat Simulation Theory, and alternative explanations are considered.</p>

The present study set out to test some of the predictions made by the Threat Simulation Theory, which suggests an evolutionary source of dreaming (Revonsuo, 2000a). The qualitative content and frequency of threatening events in dreams were compared between traumatized Swedish subjects with experience of the tsunami-disaster in Southeast Asia in 2004 with Swedish subjects with no traumatic experiences. Only a few of the hypotheses were supported by the results. The results and unsupported hypotheses are discussed with focus on the Threat Simulation Theory, and alternative explanations are considered.

This study investigates the effects of traumatic experiences on emotional content of dreams. The theoretical framework of the present study is both the threat simulation theory and Hartmann’s theory of dreams as a mechanism for handling emotions after traumatic events. Both theories predict an increase in negative emotions after trauma but assign a different function for this increase. The subjects in this study (N = 16) were regularly writing dream diaries which after the 9/11 attack gave the researchers an unique opportunity to study the exact impact of events on dream content. Each subject’s ten last dreams before 9/11, and ten first dreams after 9/11, were analysed according to the emotional content. The results showed no significant differences in the number or tone of emotions in the before dreams compared to the after dreams. Possibly because none of the subjects experienced the event first hand.

Dreaming is a complex, multimodal and sequentially organized model of the waking world (Metzinger, 2003). Nightmares are a category of dreams involving threatening scenarios, anxiety and other negative emotions (Hartmann, 1998; Nielsen &amp; Levin, 2007). Dreams and nightmares are explored in this present thesis in the light of psychology and modern cognitive neuroscience as to their nature, function and neural correlates. The three main dream theories and their leading investigations are reviewed to evaluate their evidence and overall explanatory power to account for the function of dreams and nightmares. Random Activation Theories (RATs) claim dreams are biological epiphenomena and by-products of sleep underlying mechanisms (Crick &amp; Mitchison, 1983; Flanagan, 1995, 2000a, 2000b, Hobson &amp; McCarley, 1997). Mood regulation theories consider that the psychological function of dreams is to regulate mood and help with the adaptation of individuals to their current environment such as solving daily concerns and recovery after trauma exposure (Hartmann, 1996; Levin, 1998; Stickgold, 2008; Kramer, 1991a, 1991b, 2014). Threat Simulation Theories of dreams present the evolutionary function for dreaming as a simulating off-line model of the world used to rehearse threatening events encountered in the human ancestral environment (Revonsuo, 2000a). With the threat-simulation system, threats were likely to be recognized and avoidance skills developed to guarantee reproductive success. TST consider nightmares to reflect the threat-simulation system fully activated (Revonsuo, 2000a). Supported by a robust body of evidence TST is concluded to be the most plausible theory at the moment to account as a theoretical explanation of dreams and nightmares