Consciousness can be studied only if subjective experience is documented and quantified, yet first-person accounts of the effects of brain injury on conscious experience are as rare as they are potentially useful. This report documents the alterations in waking, sleeping, and dreaming caused by a lateral medullary infarct. Total insomnia and the initial suppression of dreaming was followed by the gradual recovery of both functions. A visual hallucinosis during waking that was associated with the initial period of sleep and dream (...) suppression is described in detail. Since the changes in sleep and their recovery are comparable to results of animal experiments, it can be concluded that damage to the medullary brain stem causes extreme but short-lived alterations in conscious state and that substantial recovery occurs even though the damage to the brain stem endures. (shrink)

In The interpretation of dreams Freud famously claimed to have finally solved the riddle of dreams. Yet amidst all the heated debates and intense controversies that ensued in the wake of this groundbreaking work, one fundamental question has been entirely overlooked, namely: in what sense, exactly, are dreams analogous to riddles? It will be the burden of this paper to show that a critical investigation of this seemingly simple question reveals a fundamental and hereto unnoticed discrepancy between Freud's rhetoric on (...) his method of dream interpretation and its application in practice. More specifically, whereas Freud argues that the psychoanalytic method can effectively solve the riddles of dreams by uncovering their pre-existing solutions, careful examination reveals that dream interpretations of this kind are the product of a very different solving technique, one that proceeds along a retroactive timeline rather than a linear one. Drawing on Wittgenstein's distinction between two kinds of riddles and the manner in which they are solved, I expound on the nature of retroactive riddle-solving, thus generating a distinctly different picture of psychoanalytic dream interpretation than the one envisioned and advocated by Freud. (shrink)

Although the dream narrative, of (bio)logical necessity, originates with the dreamer, s/he typically does not know this. For the dreamer, the dream world is the real world. In this article I argue that this nightly misattribution is best explained in terms of the concept of mental ownership (e.g., Albahari, 2006; Klein, 2015a; Lane, 2012). Specifically, the exogenous nature of the dream narrative is the result of an individual assuming perspectival, but not personal, ownership of content s/he authored (i.e., “The content (...) in my head is not mine. Therefore it must be peripherally perceived”). Situating explanation within a theoretical space designed to address questions pertaining to the experienced origins of conscious content has a number of salutatory consequences. For example, it promotes predictive fecundity by bringing to light empirical generalizations whose presence otherwise might have gone unnoticed (e.g., the severely limited role of mental time travel within the dream narrative). -/- . (shrink)

Unpleasant dreams occur much more frequently than many people realise. If one is a hedonistic utilitarian – or, at least, one thinks that dreams have positive or negative moral value in virtue of their experiential quality – then one has considerable reason to try to make such dreams more positive. Given it is possible to improve the quality of our dreams, we ought to be promoting and implementing currently available interventions that improve our dream experiences, and conducting research to find (...) new, more effective interventions. (shrink)

Are subjects ever morally responsible for their dreams? In this paper I argue that if, as some theories of dreams entail, dreaming subjects sometimes express agency while they dream, then they are sometimes morally responsible for what they do and are potentially worthy of praise and blame while they dream and after they have awoken. I end by noting the practical and theoretical implications of my argument.

Dreaming: a process of self-organizationKahn and Hobson (1993) proposed that dreams are a product of self-organization of brain during sleep. As a complex system far from equilibrium state, the dreaming brain may form a new pattern by the interaction between components within this system. At REM sleep stage, signals from neuronal clusters self-organize and form image fragments, then the image fragments interact and produce images, and finally these materials are associated into a relatively continuous narrative (i.e., dreams). This process above (...) happens under a weak control of brain, and the conditions of this state mainly include: (a) the inhibition of external stimuli or feedback; (b) the changes of neuromodulatory systems (e.g., the governance of aminergic neurochemicals and the weakness of cholinergic neurochemicals); (c) the bombardment of PGO wave to the visual cortex; and (d) the changes of neural activity in brain (e.g., the activation of limbic system and the reduction of prefrontal regions). In this situation, the brain could focus on the internal world and integrate various psychological and physiological changes into dream content (Kahn et al., 2002, 2000). However, self-organization mechanism could not determine which memories will be activated and incorporated into dream content (Kahn, 2013), although it provides an approach how an ordered structure, behavior or pattern spontaneously emerges from the interaction between components or subsystems without an e... (shrink)

Must mental properties figure in psychological causal laws if they are causally efficacious? And do those psychological causal laws give the essence of mental properties? Contrary to the prevailing consensus, I argue that, on the usual conception of laws that is in play in these debates, there are in fact lawless causally efficacious properties both in and out of the philosophy of mind. I argue that this makes a great difference to the philosophical relevance of empirical psychology. 1 begin by (...) making the case that revolutions and hurricanes are lawless phenomena, before arguing for a similar thesis about creativity, love, courage, dreams, daydreams, and musings. Furthermore, the empirical research on these phenomena suggests that the philosophical issues may be independent of what empirical psychology can tell us. (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)

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. (shrink)

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. (shrink)

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)

Research in the neurosciences continues to provide evidence that sleep plays a role in the processes of learning and memory. There is less of a consensus, however, regarding the precise stages of memory development during which sleep is considered a requirement, simply favorable, or not important. This article begins with an overview of recent studies regarding sleep and learning, predominantly in the procedural memory domain, and is measured against our current understanding of the mechanisms that govern memory formation. Based on (...) these considerations, I offer a new neurocognitive framework of procedural learning, consisting first of acquisition, followed by two specific stages of consolidation, one involving a process of stabilization, the other involving enhancement, whereby delayed learning occurs. Psychophysiological evidence indicates that initial acquisition does not rely fundamentally on sleep. This also appears to be true for the stabilization phase of consolidation, with durable representations, resistant to interference, clearly developing in a successful manner during time awake (or just time, per se). In contrast, the consolidation stage, resulting in additional/enhanced learning in the absence of further rehearsal, does appear to rely on the process of sleep, with evidence for specific sleep-stage dependencies across the procedural domain. Evaluations at a molecular, cellular, and systems level currently offer several sleep specific candidates that could play a role in sleep-dependent learning. These include the upregulation of select plasticity-associated genes, increased protein synthesis, changes in neurotransmitter concentration, and specific electrical events in neuronal networks that modulate synaptic potentiation. Key Words: consolidation; enhancement; learning; memory; plasticity; sleep; stabilization. (shrink)

Models of dream analysis either assume a continuum of waking and dreaming or the existence of two dissociated realities. Both approaches rely on different methodology. Whereas continuity models are based on content analysis, discontinuity models use a structural approach. In our study, we applied both methods to test specific hypotheses about continuity or discontinuity. We contrasted dream reports of congenitally deaf-mute and congenitally paraplegic individuals with those of non-handicapped controls. Continuity theory would predict that either the deficit itself or compensatory (...) experiences would surface in the dream narrative. We found that dream form and content of sensorially limited persons was indifferent from those of non-handicapped controls. Surprisingly, perceptual representations, even of modalities not experienced during waking, were quite common in the dream reports of our handicapped subjects. Results are discussed with respect to feedforward mechanisms and protoconsciousness theory of dreaming. (shrink)

Biological realism (Revonsuo, 2001, 2006) states that dreaming is a biological phenomenon and therefore explainable in naturalistic terms, similar to the explanation of other biological phenomena. In the biological sciences, the structure of explanations can be described with the help of a framework called 'multilevel explanation'. The multilevel model provides a context that assists to clarify what needs to be explained and how, and how to place different theories into the same model. Here, I will argue that the multilevel framework (...) would be useful when we try to construct scientific explanations of dreaming. (shrink)

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...

Our goal is to develop an English version of the Dream Property Scale (DPS-E) based on the original normed scale in Japan (DPS-J). Factor analyses extracted four factors (Emotionality, Rationality, Activity, and Impression) and its factor structure was apparently similar to the DPS-J. The DPS-E was also shown to be related to EEG power spectral values. These results indicate that the DPS-E may provide an exploratory basis for a reliable and valid tool for capturing and quantifying the properties of dream (...) experiences that could reflect physiological activities without the intervention of experimenters. We suggest that the DPS-E will develop into a useful tool to help clarify dream production mechanisms by further investigation. (shrink)

Power density spectra and phase synchrony measurements were taken from intracranial electrode grids implanted in epileptic subjects. Comparisons were made between data from the waking state and from the period of unconsciousness immediately following a generalised tonic–clonic seizure. Power spectra in the waking state resembled coloured noise. Power spectra in the unconscious state resembled coloured noise from 1 to about 5 Hz, but at higher frequencies changed in two out of three subjects to resemble white noise. This boosted unconscious gamma (...) power to a higher level than conscious gamma power. For both gamma and beta passbands, synchrony measurements showed more widespread phase synchrony in the unconscious than the conscious state. We conclude that neither gamma activity per se nor phase synchrony per se are neural correlates of consciousness. (shrink)

Recent studies suggest that lucid dreaming might be associated with increased brain activity over frontal regions during rapid eye movement sleep. By applying transcranial direct current stimulation , we aimed to manipulate the activation of the dorsolateral prefrontal cortex during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with (...) the second one. According to the participants’ self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed. (shrink)

In lucid dreams the dreamer is aware of dreaming and often able to influence the ongoing dream content. Lucid dreaming is a learnable skill and a variety of techniques is suggested for lucid dreaming induction. This systematic review evaluated the evidence for the effectiveness of induction techniques. A comprehensive literature search was carried out in biomedical databases and specific resources. Thirty-five studies were included in the analysis , of which 26 employed cognitive techniques, 11 external stimulation and one drug application. (...) The methodological quality of the included studies was relatively low. None of the induction techniques were verified to induce lucid dreams reliably and consistently, although some of them look promising. On the basis of the reviewed studies, a taxonomy of lucid dream induction methods is presented. Several methodological issues are discussed and further directions for future studies are proposed. (shrink)

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)

We present Activity Analysis as a new method for the quantification of subjective reports of altered states of consciousness with regard to the indicated level of simulated motor activity. Empirical linguistic activity analysis was conducted with dream reports conceived immediately after EEG-controlled periods of hypnagogic hallucinations and REM-sleep in the sleep laboratory. Reports of REM-dreams exhibited a significantly higher level of simulated physical dreamer activity, while hypnagogic hallucinations appear to be experienced mostly from the point of passive observer. This study (...) lays the groundwork for clinical research on the level of simulated activity in pathologically altered states of subjective experience, for example in the REM-dreams of clinically depressed patients, or in intrusions and dreams of patients diagnosed with PTSD. (shrink)

Although the emotional and motivational characteristics of dreaming have figured prominently in folk and psychoanalytic conceptions of dream production, emotions have rarely been systematically studied, and motivation, never. Because emotions during sleep lack the somatic components of waking emotions, and they change as the sleeper awakens, their properties are difficult to assess. Recent evidence of limbic system activation during REM sleep suggests a basis in brain architecture for the interaction of motivational and cognitive properties in dreaming. Motivational and emotional content (...) in REM and NREM laboratory mentation reports from 25 participants were compared. Motivational and emotional content was significantly greater in REM than NREM sleep, even after controlling for the greater word count of REM reports. (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)

Cognitive theories claim, whereas non-cognitive theories deny, that cognitive access is constitutive of phenomenology. Evidence in favor of non-cognitive theories has recently been collected by Block and is based on the high capacity of participants in partial-report experiments compared to the capacity of the working memory. In reply, defenders of cognitive theories have searched for alternative interpretations of such results that make visual awareness compatible with the capacity of the working memory; and so the conclusions of such experiments remain controversial. (...) Instead of entering the debate between alternative interpretations of partial-report experiments, this paper offers an alternative line of research that could settle the discussion between cognitive and non-cognitive theories of consciousness. Here I relate the neural correlates of cognitive access to empirical research into the neurophysiology of dreams; cognitive access seems to depend on the activity of the dorsolateral prefrontal cortex. However, that area is strongly deactivated during sleep; a period when we entertain conscious experiences: dreams. This approach also avoids the classic objection that consciousness should be inextricably tied to reportability or it would fall outside the realm of science. (shrink)

The hypothesis that dreaming is involved in off-line memory processing is difficult to test because major methodological issues have to be addressed, such as dream recall and the effect of remembered dreams on memory. It would be fruitful to study the dreams of persons who use AAOM regularly.

A 1% skeptic is someone who has about a 99% credence in non-skeptical realism and about a 1% credence in the disjunction of all radically skeptical scenarios combined. The first half of this essay defends the epistemic rationality of 1% skepticism, appealing to dream skepticism, simulation skepticism, cosmological skepticism, and wildcard skepticism. The second half of the essay explores the practical behavioral consequences of 1% skepticism, arguing that 1% skepticism need not be behaviorally inert.

I reject Lindquist et al.'s implicit claim that all emotion theories other than constructionist ones subscribe to a approach. The neural mechanisms underlying relevance detection, reward, attention, conceptualization, or language use are consistent with many theories of emotion, in particular componential appraisal theories. I also question the authors' claim that the meta-analysis they report provides support for the specific assumptions of constructionist theories.

Lindquist et al. convincingly argue that the brain implements psychological operations that are constitutive of emotion rather than modules subserving discrete emotions. However, the nature of such psychological operations is open to debate. I argue that considering appraisal theories may provide alternative interpretations of the neuroimaging data with respect to the psychological operations involved.

From the neurophysiological perspective, thinking in dreaming and the quality of dream thought have been considered hallucinatory, bizarre, illogical, improbable, or even impossible. This empirical phenomenological research concentrates on testing whether dream thought can be defined as rational in the sense of an intervening mental process between sensory perception and the creation of meaning, leading to a conclusion or to taking action. From 10 individual dream journals of male participants aged 22–59 years and female participants aged 25–49 years, we delimited (...) four dreams per journal and randomly selected five thought units from each dream for scoring. The units provided a base for testing a hypothesis that the thought processes of dream construction are rational. The results support the hypothesis and demonstrate that eight fundamental rational thought processes can be applied to the dreaming process. (shrink)

The present study examined the effects of thought suppression on sleep-onset mentation. It was hypothesized that the decrease of attentional control in the transition to sleep would lead to a rebound of a suppressed thought in hypnagogic mentation. Twenty-four young adults spent two consecutive nights in a sleep laboratory. Half of the participants were instructed to suppress a target thought, whereas the other half freely thought of anything at all. To assess target thought frequency, three different measures were used in (...) the wake state and mentation reports were repeatedly prompted by a computer at sleep onset. In support of the hypothesis, results revealed a reversal of target thought frequency at sleep onset: Participants instructed to suppress reported fewer target thoughts than did controls before falling asleep, but more target thoughts afterwards. (shrink)

Although the sense of agency is often reduced if not absent in dreams, our agentive dream experiences can at times be similar to or enhanced compared to waking. The sense of agency displayed in dreams is perplexing as we are mostly shut off from real stimulus whilst asleep. Theories of waking sense of agency, in particular, comparator and holistic models, are analysed in order to argue that despite the isolation from the real environment, these models can help account for dream (...) experience. The dreamer might feel an increased sense of control of their dream bodies and a sense that they can directly control elements of the dream world. Such experiences may at times be caused by superstitious or delusional thinking due to altered cognition and changes to the sleeping brain. Here it is argued that some such experiences are akin to specific waking delusions, such as delusions of grandeur, with similar cognitive features. However, other instances of increased sense of agency in dreaming appear to be sui generis and nothing like what we experience when awake. Lucid control dreams, in which the dreamer realises that they are dreaming and that they can control the dream environment, are examples of such an experience although further nuance is required to account for their specific cognitive attributes. Future empirical research should focus on controlled dream reporting conditions in order to clarify the types of experience that occur and determine the relevant cognitive mechanisms that relate to each type. (shrink)

Integrative and naturalistic philosophy of mind can both learn from and contribute to the contemporary cognitive sciences of dreaming. Two related phenomena concerning self-representation in dreams demonstrate the need to bring disparate fields together. In most dreams, the protagonist or dream self who experiences and actively participates in dream events is or represents the dreamer: but in an intriguing minority of cases, self-representation in dreams is displaced, disrupted, or even absent. Working from dream reports in established databanks, we examine two (...) key forms of polymorphism of self-representation: dreams in which I take an external visuospatial perspective on myself, and those in which I take someone else's perspective on events. In remembering my past experiences or imagining future or possible experiences when awake, I sometimes see myself from an external or 'observer' perspective. By relating the issue of perspective in dreams to established research traditions in the study of memory and imagery, and noting the flexibility of perspective in dreams, we identify new lines of enquiry. In other dreams, the dreamer does not appear to figure at all, and the first person perspective on dream events is occupied by someone else, some other person or character. We call these puzzling cases 'vicarious dreams' and assess some potential ways to make sense of them. Questions about self-representation and perspectives in dreams are intriguing in their own right and pose empirical and conceptual problems about the nature of self-representation with implications beyond the case of dreaming. (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)

When we dream, it is often assumed, we are isolated from the external environment. It is also commonly believed that dreams can be, at times, accurate, convincing replicas of waking experience. Here I analyse some of the implications of this view for an enactive theory of conscious experience. If dreams are, as described by the received view, “inactive”, or “cranially envatted” whilst replicating the experience of being awake, this would be problematic for certain extended conscious mind theories. Focusing specifically on (...) Alva Noë’s enactive view, according to which the vehicles of perceptual experience extend beyond the brain, I argue that dreams are a quandary. Noë’s view is that dreaming is consistent with enactivism because even if dreams are inactive and shut off from the external environment, they are not “full-blown” perceptual consciousness, and also, there is some reason to reject the inactive claim. However, this view rests on an unjustified and reductive account of dreams which is not supported... (shrink)

Our eyes, bodies, and perspectives are constantly shifting as we observe the world. Despite this, we are very good at distinguishing between self-caused visual changes and changes in the environment: the world appears mostly stable despite our visual field moving around. This, it seems, also occurs when we are dreaming. As we visually investigate the dream environment, we track moving objects with our dream eyes, examine objects, and shift focus. These movements, research suggests, are reflected in the rapid movements or (...) saccades of our sleeping eyes. Do we really see the dream world in the same way that we see the real world? If we do, how could dreaming, usually assumed to be mind-generated hallucinations, replicate such an experience? This problem would be deflated if dreams are not hallucinations at all, but rather imagination, illusion or simply unrealistic. I argue that imagination and illusion views do not satisfactorily explain away the problem of vision and action in sleep. The imagination model is not a complete description of dreaming that is consistent with empirical research, and it is unlikely that the visual dream world is an illusion. Given that the dreaming visual experience is most likely active, hallucinatory, and at times a realistic world simulation, there are important implications for our understanding of visual perception and its relationship to movement. Evidence suggests that our dream eyes investigate the dream world as our waking eyes investigate the waking world. If changes to the unconsciously generated dream environment are perceived as external and unintentional while dream body movements are perceived as self-generated and intentional, current theory of visual perception may have to be expanded to account for how the dreaming mind generates a stable world in which we track and visually explore mind-generated objects. (shrink)

The distinction between phenomenal and access consciousness is central to debates about consciousness and its neural correlates. However, this distinction has often been limited to the domain of perceptual experiences. On the basis of dream phenomenology and neuroscientific findings this paper suggests a theoretical framework which extends this distinction to dreaming, also in terms of plausible neural correlates. In this framework, phenomenal consciousness is involved in both waking perception and dreaming, whereas access consciousness is weakened, but not fully eliminated, during (...) dreaming. However, access consciousness is more active during lucid dreaming. The proposed framework accounts for different aspects of dream phenomenology, including levels of integration of perceptual, cognitive and affective features in dreams, bizarreness, dream amnesia and the occurrence of meta-awareness and accessibility in lucid dreaming. Self-related experiences and their neural substrates are suggested to be differently involved in waking cognition and dreaming. Further, phenomenal consciousness during both waking and dream experiences involve widespread recurrent interactions and convergence-divergence zones in the thalamo-cortico-limbic system, activated before conscious access in global workspace areas. Finally, we discuss the relationships of the proposed framework with other neurocognitive theories and models of consciousness and major theories of dreaming, and propose novel experimental predictions. (shrink)

Individuals with Parkinson’s disease and temporal lobe epilepsy have hallucinations and mild cognitive dysfunction. The objective of this work was to study dreams in PD and TLE patients using a common functional model of dream production involving the limbic and paralimbic structures.Dreams were characterised in early-stage PD and TLE patients with dream diaries classified by the Hall van de Castle system and were compared with matched controls.In PD, there were significant differences between patients’ dreams and those of controls: animals, physical (...) aggression, and a befriender were more common in patients, and aggressor and bodily misfortunes were less common. The dreams of patients with frontal dysfunction showed more aggressive features.TLE patients had lower recall than PD patients and a higher proportion of dreams involving family and familiar settings, lower proportions involving success, and a higher incidence of frontal dysfunction.The dreams of PD and TLE patients share important features. (shrink)

To test whether mental activities collected from non-REM sleep are influenced by REM sleep, we suppressed REM sleep using clomipramine 50 mg or placebo in the evening, in a double blind cross-over design, in 11 healthy young men. Subjects were awakened every hour and asked about their mental activity. The marked REM-sleep suppression induced by clomipramine did not substantially affect any aspects of dream recall . Since long, complex and bizarre dreams persist even after suppressing REM sleep either partially or (...) totally, it suggests that the generation of mental activity during sleep is independent of sleep stage. (shrink)

Dreaming can be explained as the product of an interaction among memory processes, elaborative processes, and phenomenal awareness. A feedback circuit is activated by this interaction according to the associative links and the requirements of the dream scene. Recently, it has been hypothesized that a partial similarity exists between dreaming and mind wandering and that these two processes may involve the same neural default network. This commentary discusses the differences and similarities between phenomenal consciousness during dreaming and phenomenal consciousness during (...) mind wandering from the perspective of the “continuity” of engagement of cognitive systems. The greatest difference consists in the lack of reality testing during dreaming. Dream imagery is hallucinatory by nature. Consequently, the simulated world in dreams makes dream imagery more akin to perception. In contrast, the imagery of mind wandering is more similar to imagination. The level of meta-awareness is preserved more frequ... (shrink)