There is wide agreement among dream researchers that emotional memories are activated during dreaming and that emotions play an important role in the thematic development of the dream. In accordanc...

Hallucinatory states are experienced not only in connection with drugs and psychopathologies but occur naturally and spontaneously across the human circadian cycle: Our nightly dreams bring multimodal experiences in the absence of adequate external stimuli. The current study proposes a new, tighter measure of these hallucinatory states: Sleep onset, REM sleep, and non-REM sleep are shown to differ with regard to motor imagery indicating interactions with a rich imaginative world, and cognitive agency that could enable sleepers to recognize their hallucinatory (...) state. Mentation reports from the different states were analysed quantitatively with regard to two grammatical–semantic constructs, motor agency and cognitive agency. The present results support earlier physiological and psychological evidence in revealing a decline in cognitive functions and an increase in simulated interactions with a hallucinatory world, en route to normal REM sleep. This leads us to introduce the hypothesis that REM sleep, which exhibits remarkably high levels of sensorimotor processes, may have evolved to serve as a virtual laboratory for the development and rehearsal of embodied cognition. The new measure of hallucinatory states presented here may also hold implications for the study of executive functions and cognitions, which might be interesting, for example, for the investigation of lucid dreaming. (shrink)

Revonsuo’s influential Threat Simulation Theory predicts that people exposed to survival threats will have more threat dreams, and evince enhanced responses to dream threats, compared to those living in relatively safe conditions. Participants in a high crime area differed significantly from participants in a low crime area in having greater recent exposure to a life-threatening event . Contrary to TST’s predictions, the SA participants reported significantly fewer threat dreams , and did not differ from the Welsh participants in responses to (...) dream threats . Overall, the incidence of threat in dreams was extremely low—less than 20% of dreams featured realistic survival threats. Escape from dream threats occurred in less than 2% of dreams. We conclude that this evidence contradicts key aspects of TST. (shrink)

Malcolm-Smith, Solms, Turnbull and Tredoux [Malcolm-Smith, S., Solms, M., Turnbull, O., & Tredoux, C. . 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. . The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23, 877-901.; Revonsuo, A. . 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. . 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. (shrink)

The experience of skilled action occurs in dreams if we take dream reports at face value. However, what these reports indicate requires nuanced analysis. It is uncertain what it means to perform any action in a dream whatsoever. If skilled actions do occur in dreams, this has important implications for both theory of action and theory of dreaming. Here, it is argued that since some dreams generate a convincing, hallucinated world where we have virtual bodies that interact with virtual objects, (...) there is a sense in which we can perform virtual actions. Further, we can also perform skilfully, although not all apparent skilful performance is as it seems. Since the dream world is generated by the dreamer’s own mind, it can be difficult to determine whether the dream world simply allows goals to be achieved without the abilities that would be required in a similar waking scenario. Because of this, individual dream reports alone are insufficient to determine what skills are demonstrated in a particular dream. However, taken with evidence from REM sleep behaviour disorder, incompetent dreams, lucid dreams and motor-skill practise, it is likely that skilled virtual dream performance at times involves both opportunity for virtual behaviour and the display of competence. Evidence from cognitive science suggests that dreamers can also lose competence through forgetting and other cognitive incapacities but, more surprisingly, it is possible to gain abilities in a robust sense, consistent with the idea that some dreams, at least, are virtual realities rather than imagination. (shrink)

Artykuł zawiera prezentację i dyskusję wybranych zagadnień świadomości śniącej. Pierwsze z nich dotyczy znaczenia adaptacyjnego świadomości podczas snu. Drugie zagadnienie obejmuje charakterystykę kognitywnej świadomości śniącej. Efektem krytycznego przeglądu badań i koncepcji jest teza, że: (1) świadomość śniąca nie ma charakteru adaptacji biologicznej, (2) świadomość śniąca jest formą zdegradowanej reprezentacji kognitywnej w porównaniudo świadomości w stanie czuwania. W szczególności świadomość śniąca zawiera deficyty intencjonalności (uwagi) oraz wyższych form kognitywnych, w tym dysfunkcji wykonawczych.

The influential threat simulation theory 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 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. (shrink)

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. . Dream imagery becomes more intense after 9/11/01. Dreaming, 13, 61–66; Hartmann, E., & Brezler, T. . A systematic change in dreams (...) after 9/11/01. Sleep, 31, 213–218], the media exposure factor postulated by Propper [Propper, R. E., Stickgold, R., Keeley, R., & Christman, S. D. . Is television traumatic? Dreams, stress, and media exposure in the aftermath of September 11, 2001. Psychological Science, 18, 334–340], the continuity hypothesis of Domhoff [Domhoff, W. G. . Finding meaning in dreams: A quantitative approach. New York: Plenum], the cognitive and metacognitive approach of Kahan [Kahan, T. L. . Consciousness in dreaming: A metacognitive approach. In K. Bulkeley , Dreams: A reader on the religious, cultural, and psychological dimensions of dreaming . New York: Palgrave], and the threat simulation theory of Revonsuo [Revonsuo, A. . The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23, 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. (shrink)

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 and a control condition. 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. (shrink)

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain (...) activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation. (shrink)

In humans, conscious perception and cognition depends upon the thalamocortical complex, which supports perception, explicit cognition, memory, language, planning, and strategic control. When parts of the T-C system are damaged or stimulated, corresponding effects are found on conscious contents and state, as assessed by reliable reports. In contrast, large regions like cerebellum and basal ganglia can be damaged without affecting conscious cognition directly. Functional brain recordings also show robust activity differences in cortex between experimentally matched conscious and unconscious events. This (...) basic anatomy and physiology is highly conserved in mammals and perhaps ancestral reptiles. While language is absent in other species, homologies in perception, memory, and motor cortex suggest that consciousness of one kind or another may be biologically fundamental and phylogenetically ancient. In humans we infer subjective experiences from behavioral and brain evidence. This evidence is quite similar in other mammals and perhaps some non-mammalian species. On the weight of the biological evidence, therefore, subjectivity may be conserved in species with human-like brains and behavior. (shrink)

Malcolm-Smith, Solms, Turnbull and Tredoux [Malcolm-Smith, S., Solms, M.,Turnbull, O., & Tredoux, C. . Threat in dreams: An adaptation? Consciousness and Cognition, 17, 1281–1291.] have made an attempt to test the Threat-Simulation Theory , a theory offering an evolutionary psychological explanation for the function of dreaming [Revonsuo, A. . The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23, 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. (shrink)