Sleep is phenomenologically rich, teeming with different kinds of conscious thought and experience. Dreaming is the most prominent example, but there is more to conscious experience in sleep than dreaming. Especially in non‐rapid eye movement sleep, conscious experience, sometimes dreamful, sometimes dreamless, also alternates with a loss of consciousness. Yet while dreaming has become established as a topic for interdisciplinary consciousness science and empirically informed philosophy of mind, the same is not true of other kinds of sleep‐related experience, nor is (...) it true of sleep itself. I argue that this is a mistake. Conscious experience in sleep is more diverse than dreaming and we need to explain its different forms as well as the alternation between conscious and unconscious sleep states. We also need to ask how different kinds of sleep‐related experience relate to foundational issues about sleep and wakefulness as well as sleep stages. I survey recent findings and theoretical developments from sleep and dream research to show how the traditional view of sleep and its relation to wakefulness and consciousness is flawed. I then suggest that by refining our frameworks of sleep‐related experiences and sleep staging in tandem, we can work toward a better view. As we are only beginning to understand the diversity of consciousness in sleep, an important aim is programmatic: We need a philosophy of sleep and of consciousness in sleep, not just a philosophy of dreaming, and a future theory of sleep needs to integrate phenomenological considerations with neuroscientific and behavioral evidence. Working toward such a theory will radically transform our understanding of sleep, wakefulness, and our conscious minds. (shrink)

Llewellyn's proposal that rapid eye movement dreaming reflects elaborative encoding mediated by the hippocampus offers an interesting perspective for understanding hallucinations accompanying sleep paralysis. SP arises from anomalous intrusion of REM processes into waking consciousness, including threat-detection systems mediated by the amygdala. Unique aspects of SP hallucinations offer additional prospects for investigation of Llewellyn's theory of elaborative encoding.

Nielsen [Nielsen, T. . Felt presence: Paranoid delusion or hallucinatory social imagery? Consciousness and Cognition, 16, 975–983.] raises a number of issues and presents several provocative arguments worthy of discussion regarding the experience of the felt presence during sleep paralysis . We consider these issues beginning with the nature of FP and its relation to affective-motivational systems and provide an alternative to Nielsen’s reduction of FP to a purely spatial hallucination. We then consider implications of the “normal social imagery” model. (...) We can find only one specific empirical hypothesis articulated within this framework and it turns out to be one that we explicitly addressed in our original paper. We also review our position regarding the possible relation of FP during SP to a number of related anomalous experiences and contrast FP to anomalous vestibular-motor phenomena. We review our position that the neuromatrix concept, in the light of available evidence, is more appropriately applied to V-M experiences than FP. Finally, we pursue speculations, raised in Nielsen’s commentary, on the wider implications of FP. (shrink)

Isolated sleep paralysis is a common parasomnia characterized by an inability to move or speak and often accompanied by hallucinations of a sensed presence nearby. Recent research has linked ISP, and sensed presence more particularly, with social anxiety and other psychopathologies. The present study used a large sample of respondents to an internet questionnaire to test whether these associations are due to a general personality factor, affect distress, which is implicated in nightmare suffering and hypothesized to involve dysfunctional social imagery (...) processes. A new measure, ISP distress, was examined in relation to features of ISP experiences, to self-reported psychopathological diagnosis, to scores on the Leibowitz Social Anxiety Scale and to scores on a new questionnaire subscale assessing social imagery in a variety of waking states. Three main results were found: ISP experiences are only weakly associated with a prior diagnosis of mental disorder, sensed presence during ISP is associated preferentially with ISP distress, and ISP distress is associated with dysfunctional social imagery. A general predisposition to affective distress may influence the distress associated with ISP experiences; overly passive social imagery may, in turn, be implicated in this affect distress influence. (shrink)

The paper proposes a minimal definition of dreaming in terms of immersive spatiotemporal hallucination (ISTH) occurring in sleep or during sleep–wake transitions and under the assumption of reportability. I take these conditions to be both necessary and sufficient for dreaming to arise. While empirical research results may, in the future, allow for an extension of the concept of dreaming beyond sleep and possibly even independently of reportability, ISTH is part of any possible extension of this definition and thus is a (...) constitutive condition of dreaming. I also argue that the proposed ISTH model of dreaming, in conjunction with considerations on the epistemic relationship between dreaming and dream reports, raises important questions about the extent to which dreams typically involve a detailed body representation—an assumption that plays an important role in philosophical work on dreaming. As a commonly accepted definition of dreaming is lacking in current dream research, the ISTH model, which integrates conceptual analysis and epistemological considerations with results from empirical research, is an important contribution to this field. By linking dreaming to felt presence, full-body illusions, and autoscopic phenomena such as out-of-body experiences in wakefulness and in the hypnagogic state, the ISTH model of dreaming also helps integrate dream research, both theoretically and experimentally, with the study of other altered states of consciousness involving hallucinations. It makes straightforward and investigable predictions by claiming that all of these experiences have amodal spatiotemporal hallucinations as their common denominator. Finally, it is theoretically relevant for the philosophical discussion on minimal phenomenal selfhood. (shrink)

Felt presence, a sensation that “someone is there”, is an integral part of our everyday experience. It can manifest itself in a variety of forms ranging from most subtle fleeting impressions to intense hallucinations of demonic assault or visions of the divine. Felt presence phenomenon outside of the context of neurological disorders is largely neglected and not well understood by contemporary science. This paper focuses on the experiential and expressive qualities of the phenomenon and attempts to bring forth the complexity (...) and the richness of possibilities for inter- and intrasubjective awareness represented by these experiences. Are these simply misperceptions and hallucinations heightened and enforced by the mystical or superstitious mind? Or are these entities projections of our own “selves”, elements of self-estrangement? How are such experiences shaping our understanding of ourselves and of others? And finally, what is the interplay between intersubjective, private experiences and private or public spaces of dwelling? (shrink)

Sleep-related experiences [Watson, D. . Dissociations of the night: Individual differences in sleep-related experiences and their relation to dissociation and schizotypy. Journal of Abnormal Psychology, 110, 526–535] refer to a host of nocturnal altered-consciousness phenomena, including narcoleptic tendencies, nightmares, problem-solving dreams, waking dreams, and lucid dreams. In an attempt to clarify the meaning of this construct, we examined cross-sectional and longitudinal associations of sleep-related experiences , altered-consciousness tendencies , psychological distress, childhood maltreatment , and life stress in young adults. Both (...) types of SREs were found to be distinguishable from altered-consciousness tendencies. Transliminality emerged as a longitudinal predictor of both general SREs and lucid dreams. Psychological distress and an increase in life stress predicted an increase in general SREs over a 3-month interval. We conclude that transliminality is a general altered-consciousness trait that accounts for some of the individual differences in sleep-related experiences, and that general sleep experiences are an outcome of psychological distress and life stress. (shrink)