Jennifer Michelle Windt

Measuring consciousness in dreams: The lucidity and consciousness in dreams scale

In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream.

How to integrate dreaming into a general theory of consciousness—A critical review of existing positions and suggestions for future research

In this paper, we address the different ways in which dream research can contribute to interdisciplinary consciousness research. As a second global state of consciousness aside from wakefulness, dreaming is an important contrast condition for theories of waking consciousness. However, programmatic suggestions for integrating dreaming into broader theories of consciousness, for instance by regarding dreams as a model system of standard or pathological wake states, have not yielded straightforward results. We review existing proposals for using dreaming as a model system, taking into account concerns about the concept of modeling and the adequacy and practical feasibility of dreaming as a model system. We conclude that existing modeling approaches are premature and rely on controversial background assumptions. Instead, we suggest that contrastive analysis of dreaming and wakefulness presents a more promising strategy for integrating dreaming into a broader research context and solving many of the problems involved in the modeling approach.

Reporting dream experience: Why (not) to be skeptical about dream reports.

Are dreams subjective experiences during sleep? Is it like something to dream, or is it only like something to remember dreams after awakening? Specifically, can dream reports be trusted to reveal what it is like to dream, and should they count as evidence for saying that dreams are conscious experiences at all? The goal of this article is to investigate the relationship between dreaming, dream reporting and subjective experience during sleep. I discuss different variants of philosophical skepticism about dream reporting and argue that they all fail. Consequently, skeptical doubts about the trustworthiness of dream reports are misguided, and for systematic reasons. I suggest an alternative, anti-skeptical account of the trustworthiness of dream reports. On this view, dream reports, when gathered under ideal reporting conditions and according to the principle of temporal proximity, are trustworthy (or transparent) with respect to conscious experience during sleep. The transparency assumption has the status of a methodologically necessary default assumption and is theoretically justified because it provides the best explanation of dream reporting. At the same time, it inherits important insights from the discussed variants of skepticism about dream reporting, suggesting that the careful consideration of these skeptical arguments ultimately leads to a positive account of why and under which conditions dream reports can and should be trusted. In this way, moderate distrust can be fruitfully combined with anti-skepticism about dream reporting. Several perspectives for future dream research and for the comparative study of dreaming and waking experience are suggested.

Does Consciousness Disappear in Dreamless Sleep

Consciousness is often said to disappear in deep, dreamless sleep. We argue that this assumption is oversimplified. Unless dreamless sleep is defined as unconscious from the outset there are good empirical and theoretical reasons for saying that a range of different types of sleep experience, some of which are distinct from dreaming, can occur in all stages of sleep. We introduce a novel taxonomy for describing different kinds of dreamless sleep experiences and suggest research methods for their investigation. Future studies should focus on three areas: memory consolidation, sleep disorders, and sleep state (mis)perception. Our proposal suggests new directions for sleep and dream science, as well as for the neuroscience of consciousness, and can also inform the diagnosis and treatment of sleep disorders.

Tickle me, I think I might be dreaming! Sensory attenuation, self-other distinction, and predictive processing in lucid dreams

The contrast between self- and other-produced tickles, as a special case of sensory attenuation for self-produced actions, has long been a target of empirical research. While in standard wake states it is nearly impossible to tickle oneself, there are interesting exceptions. Notably, participants awakened from REM (rapid eye movement-) sleep dreams are able to tickle themselves. So far, however, the question of whether it is possible to tickle oneself and be tickled by another in the dream state has not been investigated empirically or addressed from a theoretical perspective. Here, we report the results of an explorative web-based study in which participants were asked to rate their sensations during self-tickling and being tickled during wakefulness, imagination, and lucid dreaming. Our results, though highly preliminary, indicate that in the special case of lucid control dreams, the difference between self-tickling and being tickled by another is obliterated, with both self- and other produced tickles receiving similar ratings as self-tickling during wakefulness. This leads us to the speculative conclusion that in lucid control dreams, sensory attenuation for self-produced tickles spreads to those produced by non-self dream characters. These preliminary results provide the backdrop for a more general theoretical and metatheoretical discussion of tickling in lucid dreams in a predictive processing framework. We argue that the primary value of our study lies not so much in our results, which are subject to important limitations, but rather in the fact that they enable a new theoretical perspective on the relationship between sensory attenuation, the self-other distinction and agency, as well as suggest new questions for future research. In particular, the example of tickling during lucid dreaming raises the question of whether sensory attenuation and the self-other distinction can be simulated largely independently of external sensory input.

Just in Time—Dreamless Sleep Experience as Pure Subjective Temporality

In this commentary, I propose a strategy for extending Evan Thompson’s argument on the existence of dreamless sleep experience. My first aim is to show that the Indian debate on reports of having slept peacefully is importantly similar to debates in scientific dream research and contemporary Western philosophy on the trustworthiness of dream reports. This analogy leads to a surprising conclusion: the default view of conscious experience as that which disappears in dreamless sleep, though widely accepted in cognitive neuroscience, is in fact inconsistent with the methodological background assumptions of scientific dream research. Importantly, the methods already used in scientific dream research, as well as the theoretical justification on which they are based, can be extended to the investigation of dreamless sleep experience. Second, I sketch the outlines of a conceptual model of dreamless sleep experience as involving pure subjective temporality, or phenomenal experience characterized only by the phenomenal now and the sense of duration, but devoid of any further intentional content. I suggest that understood in this manner, dreamless sleep experience is a candidate for minimal phenomenal experience, or the simplest form in which a state can be phenomenally conscious. This model also extends existing work on minimal phenomenal selfhood in dreams. Third, I discuss three empirical examples that I take to be particularly promising candidates of dreamless sleep experience. These are certain forms of minimal or imageless lucid dreams, white dreams, and sleep-state misperception of the type most dramatically seen in subjective insomnia.

Predictive brains, dreaming selves, sleeping bodies: how the analysis of dream movement can inform a theory of self- and world-simulation in dreams

In this paper, I discuss the relationship between bodily experiences in dreams and the sleeping, physical body. I question the popular view that dreaming is a naturally and frequently occurring real-world example of cranial envatment. This view states that dreams are functionally disembodied states: in a majority of dreams, phenomenal experience, including the phenomenology of embodied selfhood, unfolds completely independently of external and peripheral stimuli and outward movement. I advance an alternative and more empirically plausible view of dreams as weakly phenomenally-functionally embodied states. The view predicts that bodily experiences in dreams can be placed on a continuum with bodily illusions in wakefulness. It also acknowledges that there is a high degree of variation across dreams and different sleep stages in the degree of causal coupling between dream imagery, sensory input, and outward motor activity. Furthermore, I use the example of movement sensations in dreams and their relation to outward muscular activity to develop a predictive processing account. I propose that movement sensations in dreams are associated with a basic and developmentally early kind of bodily self-sampling. This account, which affords a central role to active inference, can then be broadened to explain other aspects of self- and world-simulation in dreams. Dreams are world-simulations centered on the self, and important aspects of both self- and world-simulation in dreams are closely linked to bodily self-sampling, including muscular activity, illusory own-body perception, and vestibular orienting in sleep. This is consistent with cognitive accounts of dream generation, in which long-term beliefs and expectations, as well as waking concerns and memories play an important role. What I add to this picture is an emphasis on the real-body basis of dream imagery. This offers a novel perspective on the formation of dream imagery and suggests new lines of research.

On the importance of 19th century dream research: Progress in dream research between Aristotle’s work on dreaming and the discovery of REM sleep

Barbera’s [1] review about the development of dream theories in Greek and Roman philosophy is well researched and enjoyable to read, but its conclusion seems somewhat surprising and unsubstantiated. In particular, we disagree with the closing statement that little progress was made in the understanding of dreaming between Aristotle’s writings and the discovery of REM sleep in the 1960s. Of course, the discovery of REM sleep was arguably the most significant advancement in dream research to this day. Nonetheless, considerable progress was made during the 18th and 19th centuries. Whereas the specific phenomenology of dreaming was not extensively discussed by Greek and Roman authors, the focus of contemporary dream research on the analysis of subjective dream content and the systematic use of dream reports was already anticipated by 19th century researchers. For example, Mary Calkins [2] was the first to attempt a statistical analysis of dream reports, and Alfred Maury [3] used systematic awakenings to elicit dream reports and investigate the influence of external stimuli on dreams. Other researchers focused on the physiology of dreaming, for instance, by observing that lesions in the occipito-temporal area may cause a virtually complete cessation of dreaming [4] or even by associating dreaming with periods of eye movement activity in sleep [5]. At the same time, even today, many studies based on home dream diaries provide new and important insights without referring to sleep stages and thus rely on essentially the same methodology as 19th century dream research. Finally, it should be pointed out that dreaming was an important topic of investigation not only in antiquity, but throughout the history of philosophy [6]. While many of the questions discussed by Greek and Roman authors anticipated later dream theories, their answers often differed from those given by medieval and modern philosophers – and in important ways. Acknowledgments

Kognitionswissenschaften und Philosophie des Geistes

Die Fluchtigkeit der Traume ist sprichwortlich, stellt jedoch gleichzeitig eine wichtige Herausforderung fur die philosophische Theoriebildung und die empirische Traumforschung dar. Sie manifestiert sich aber auch auf der personlichen Ebene in der Fluchtigkeit der Traumerinnerung.

Sny, świadomość i jaźń: Perspektywa filozoficzna

Artykul jest przeglądem badan dotyczących snu i śnienia, proponuje rowniez nowe metody badawcze, umozliwiające analize świadomych doświadczen podczas snu. Biorąc pod uwage rozwoj wiedzy na ten temat, zarowno w dziedzinie nauk ścislych, jak i filozofii, autorka wskazuje nowe kierunki rozwoju filozoficznej teorii snu i związanych z nią koncepcji śnienia, jaźni i świadomości. Analizując fenomenologie snow oraz relacje miedzy fizycznym cialem we śnie i śniącym „ja”, artykul zwraca tez uwage na alternatywne stany świadomości i ich związek ze snami i śnieniem.