This study examined the laboratory dream content reported by 14 patients with schizophrenia and 15 controls, with a focus on reports obtained from NonREM sleep. Both the controls’ and patients’ frequency of dream recall following awakenings from NonREM and REM sleep were similar to values reported for healthy participants. Patients’ NonREM sleep narratives were shorter than those from controls. When compared to their reports from REM sleep, both groups’ NonREM sleep reports included significantly fewer words (...) and reportable items. The controls were more likely to report a subjective feeling of bizarreness for their REM sleep reports as compared to their NonREM sleep reports. This difference was not observed in patients with schizophrenia. Taken together, these findings suggest few differences between the NonREM sleep mentation of patients with schizophrenia and of controls and that sleep stage cognitive style is comparable in both groups, with NonREM sleep reports being more thought-like, less elaborate and bizarre than REM sleep reports. (shrink)

Numerous studies have replicated the finding of mentation in both rapid eye movement (REM) and nonrapid eye movement (NREM) sleep. However, two different theoretical models have been proposed to account for this finding: (1) a one-generator model, in which mentation is generated by a single set of processes regardless of physiological differences between REM and NREM sleep; and (2) a two-generator model, in which qualitatively different generators produce cognitive activity in the two states. First, research is (...) reviewed demonstrating conclusively that mentation can occur in NREM sleep; global estimates show an average mentation recall rate of about 50% from NREM sleep – a value that has increased substantially over the years. Second, nine different types of research on REM and NREM cognitive activity are examined for evidence supporting or refuting the two models. The evidence largely, but not completely, favors the two-generator model. Finally, in a preliminary attempt to reconcile the two models, an alternative model is proposed that assumes the existence of covert REM sleep processes during NREM sleep. Such covert activity may be responsible for much of the dreamlike cognitive activity occurring in NREM sleep. Key Words: cognition in sleep; dreaming; NREM sleep; REM sleep; sleep mentation. (shrink)

Whereas many researchers see a heuristic potential in the covert REM sleep model for explaining NREM sleep mentation and associated phenomena, many others are unconvinced of its value. At present, there is much circumstantial support for the model, but validation is lacking on many points. Supportive findings from several additional studies are summarized with results from two new studies showing (1) NREM mentation is correlated with duration of prior REM sleep, and (2) REM sleep (...) signs (eye movements, phasic EMG) occur frequently in NREM sleep. The covert REM sleep model represents one class of explanatory models that combines the two assumptions of mind-body isomorphism and a 1-gen mentation generator; its future development will depend largely upon a more detailed understanding of sleep state interactions and their contribution to mind-body isomorphisms. (shrink)

The "Nightcap," a relatively nonintrusive and "user-friendly" sleep monitoring system, was used by 11 subjects on 10 consecutive nights in their homes. Eighty-eight sleep mentation reports were obtained after spontaneous awakenings from Nightcap-identified REM sleep and 61 were obtained from NREM awakenings. Sleep mentation was recalled in 83% of REM reports and 54% of NREM reports. The median length of REM reports was 148 words compared to 21 words for NREM reports. Twenty-four percent of (...) the REM reports were over 500 words long; no NREM reports over 500 words were obtained. REM report lengths were lowest during the first 15 min of the REM cycle and longest 15–45 min into the period. In contrast, 7 of the 9 NREM reports more than 100 words long occurred within the first 15 min of NREM periods. The Nightcap thus appears to be an effective and efficient method of collecting large numbers of sleep mentation reports with correlated sleep staging under normal ecological conditions. (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)

This study tested the two main neurocognitive models of dreaming by using cognitive data elicited from REM sleep in normals and narcoleptics. The two models were the ''activation-only'' view which holds that, in the context of sleep, overall activation of the brain is sufficient for consciousness to proceed in the manner of dreaming (e.g., Antrobus, 1991; Foulkes, 1993; Vogel, 1978); and the Activation, Input source, Modulation (AIM model), which predicts that not only brain activation level but also neurochemical (...) modulatory systems exert widespread effects upon dreaming (Hobson & McCarley, 1977; Hobson, Pace-Schott, & Stickgold, 2000). Mental activity was studied in nocturnal REM in 15 narcoleptics and 9 normal healthy persons and in REM at the onset of daytime naps and nighttime sleep (SOREM) in narcoleptics. The study was performed in the subjects' homes, using instrumental awakenings and ambulatory polysomnographic techniques, and focused upon visual vividness, mentation report length, improbable and discontinuous bizarre features, and reflective consciousness. Within each subject group, most cognitive variables tended to fluctuate in line with expected variations in circadian activation level. When comparing the cognitive variables between the two groups, reflective consciousness was clearly highest in narcoleptics, whereas improbabilities and discontinuities were lower, with mentation report length and visual vividness differing less between the groups. These findings are consistent with the AIM model of sleep mentation, but not with the activation-only model. (shrink)

Sleep and dreaming are important daily phenomena that are receiving growing attention from both the scientific and the philosophical communities. The increasingly popular predictive brain framework within cognitive science aims to give a full account of all aspects of cognition. The aim of this paper is to critically assess the theoretical advantages of Predictive Processing (PP, as proposed by Clark 2013, Clark 2016; and Hohwy 2013) in defining sleep and dreaming. After a brief introduction, we overview the state (...) of the art at the intersection between dream research and PP (with particular reference to Hobson and Friston 2012; Hobson et al. 2014). In the following sections we focus on two theoretically promising aspects of the research program. First, we consider the explanations of phenomenal consciousness during sleep (i.e. dreaming) and how it arises from the neural work of the brain. PP provides a good picture of the peculiarity of dreaming but it can’t fully address the problem of how consciousness comes to be in the first place. We propose that Integrated Information Theory (IIT) (Oizumi et al. 2014; Tononi et al. 2016) is a good candidate for this role and we will show its advantages and points of contact with PP. After introducing IIT, we deal with the evolutionary function of sleeping and dreaming. We illustrate that PP fits with contemporary researches on the important adaptive function of sleep and we discuss why IIT can account for sleep mentation (i.e. dreaming) in evolutionary terms (Albantakis et al. 2014). In the final section, we discuss two future avenues for dream research that can fruitfully adopt the perspective offered by PP: (a) the role of bodily predictions in the constitution of the sleeping brain activity and the dreaming experience, and (b) the precise role of the difference stages of sleep (REM (Rapid eye movement), NREM (Non-rapid eye movement) in the constitution and refinement of the predictive machinery. (shrink)

Both Solms and Nielsen acknowledge the difficulty of accounting for the similarities between REM and NREM sleep mentation with a two-generator model, and each link dreams, either explicitly (Solms) or implicitly (Nielsen), to brain activation. At present, however, no data indicate that brain activation can be demonstrated whenever vivid dream reports are obtained. [Nielsen; Solms].

Nielsen's model presents a new isomorphic brain-mind viewpoint, according to which the sole dream generator is found in a REM-on (explicit or covert REM) mechanism. Such a model cannot explain the dreamlike activity during SWS (slow wave sleep), SO (sleep onset) and in the last period of sleep. Moreover the hypothesis contrasts with Solms's data, which show that dreaming is present also in case of destruction of the REM generator. [Nielsen; Solms].

The validity of dream recall is discussed. What is the relation between the actual dream and its later reflection? Nielsen proposes differential sleep mentation, which is probably determined by dream accessibility. Solms argues that REM sleep and dreaming are double dissociable states. Dreaming occurs outside REM sleep when cerebral activation is high enough. That various active sleep states correlate with vivid dream reports implies that REM sleep and dreaming are single dissociable states. Vertes & (...) Eastman reject that REM sleep is involved in memory consolidation. Considerable evidence for this was obtained by REM deprivation studies with the dubious water tank technique. [Nielsen; Solms; Vertes & Eastman]. (shrink)

Primary and secondary processes are the foundational axes of the Freudian mental apparatus: one horizontally as a tendency to associate, the primary process, and one vertically as the ability for perspective taking, the secondary process. Primary process mentation is not only supposed to be dominant in the unconscious but also, for example, in dreams. The present study tests the hypothesis that the mental activity during REM-sleep has more characteristics of the primary process, while during non-REM-sleep more secondary (...) process operations take place. Because the solving of a rebus requires the ability to non-contexually condensate the literal reading of single stimuli into a new one, rebus solving is a primary process operation by excellence. In a replication of the dream-rebus study of Shevrin and Fisher (1967), a rebus, which consisted of an image of a comb (German: “Kamm”) and an image of a raft (German: “Floß”), resulting in the German rebus word “kampflos” (Engl.: without a struggle), was flashed subliminally (at 1 ms) to 20 participants before going to sleep. Upon consecutive awakenings participants were asked for a dream report, free associations and an image description. Based on objective association norms, there were significantly more conceptual associations referring to Kamm and Floß indexing secondary process mentation when subjects were awakened from non-REM sleep as compared to REM-awakenings. There were not significantly more rebus associations referring to kampflos indexing primary process mentation when awakened from REM-sleep as compared to non-REM awakenings. However, when the associations were scored on the basis of each subject’s individual norms, there was a rebus effect with more idiosyncratic rebus associations in awakenings after REM than after non-REM-sleep. Our results support the general idea that REM-sleep is characterized by primary process thinking, while non-REM-sleep mentation follows the rules of the secondary process. (shrink)

This paper presents a pilot study that explores instances of objectless awareness during sleep: conscious experiences had during sleep that prima facie lack an object of awareness. This state of objectless awareness during sleep has been widely described by Indian contemplative traditions and has been characterised as a state of consciousness-as-such; while in it, there is nothing to be aware of, one is merely conscious (cf. Evans-Wentz, 1960; Fremantle, 2001; Ponlop, 2006). While this phenomenon has received diferent (...) names in the literature, such as ‘witnessing-sleep’ and ‘clear light sleep’ among others, the specifc phenomenological profle of this state has not yet been rigorously studied. This paper aims at presenting a preliminary investigation of objectless consciousness during sleep using a novel tool in qualitative research that can guide future research. Five participants experiencing objectless consciousness during sleep were interviewed following the Micro-phenomenological Interview technique (MPI; Petitmengin, 2005, 2006). All participants reported an experience they had during sleep in which there was no scenery and no dream. This period labelled as ‘No Scenery/Void’ was either preceded by the dissolution of a lucid dream or by other forms of conscious mentation. The analysis of the results advances four experiential dimensions during this state of void, namely (1) Perception of absence, (2) Self-perception, (3) Perception of emotions, and (4) Perception of awareness. While the results are primarily explorative, they refer to themes found in the literature to describe objectless sleep and point at potential avenues of research. The results from this study are taken as indications to guide future operationalisations of this phenomenon. (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)

This paper presents a pilot study that explores instances of objectless awareness during sleep: conscious experiences had during sleep that prima facie lack an object of awareness. This state of objectless awareness during sleep has been widely described by Indian contemplative traditions and has been characterised as a state of consciousness-as-such; while in it, there is nothing to be aware of, one is _merely_ conscious (cf. Evans-Wentz, 1960 ; Fremantle, 2001 ; Ponlop, 2006 ). While this phenomenon (...) has received different names in the literature, such as ‘witnessing-sleep’ and ‘clear light sleep’ among others, the specific phenomenological profile of this state has not yet been rigorously studied. This paper aims at presenting a preliminary investigation of objectless consciousness during sleep using a novel tool in qualitative research that can guide future research. Five participants experiencing objectless consciousness during sleep were interviewed following the _Micro-phenomenological Interview_ technique (MPI; Petitmengin, 2005, 2006 ). All participants reported an experience they had during sleep in which there was no scenery and no dream. This period labelled as ‘No Scenery/Void’ was either preceded by the dissolution of a lucid dream or by other forms of conscious mentation. The analysis of the results advances four experiential dimensions during this state of void, namely (1) Perception of absence, (2) Self-perception, (3) Perception of emotions, and (4) Perception of awareness. While the results are primarily explorative, they refer to themes found in the literature to describe objectless sleep and point at potential avenues of research. The results from this study are taken as indications to guide future operationalisations of this phenomenon. (shrink)

The nature and time course of sleep onset (hypnagogic) mentation was studied in the home environment using the Nightcap, a reliable, cost-effective, and relatively noninvasive sleep monitor. The Nightcap, linked to a personal computer, reliably identified sleep onset according to changes in perceived sleepiness and the appearance of hypnagogic dream features. Awakenings were performed by the computer after 15 s to 5 min of sleep as defined by eyelid quiescence. Awakenings from longer periods of (...) class='Hi'>sleep were associated with (1) an increase in reported sleepiness, (2) a decrease in the length of mentation reports, (3) a decrease in the frequency of reports of normal, wake-like thoughts, (4) an increase in the frequency of ''unusual thoughts,'' and (5) increased frequencies of formal dream features, including visual hallucination, self-representation, fictive movement, narrative plot, and bizarreness. While sleep-onset reports can include all features of rapid eye movement (REM) dream reports, the number of such features is markedly reduced at sleep onset, suggesting that this mentation is a greatly diminished version of REM dreaming. (shrink)

The nature and time course of sleep onset mentation was studied in the home environment using the Nightcap, a reliable, cost-effective, and relatively noninvasive sleep monitor. The Nightcap, linked to a personal computer, reliably identified sleep onset according to changes in perceived sleepiness and the appearance of hypnagogic dream features. Awakenings were performed by the computer after 15 s to 5 min of sleep as defined by eyelid quiescence. Awakenings from longer periods of sleep (...) were associated with an increase in reported sleepiness, a decrease in the length of mentation reports, a decrease in the frequency of reports of normal, wake-like thoughts, an increase in the frequency of “unusual thoughts,” and increased frequencies of formal dream features, including visual hallucination, self-representation, fictive movement, narrative plot, and bizarreness. While sleep-onset reports can include all features of rapid eye movement dream reports, the number of such features is markedly reduced at sleep onset, suggesting that this mentation is a greatly diminished version of REM dreaming. (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)

By assuming that REM sleep either plays a critical role in all memory consolidation or no role in any, Vertes & Eastman have chosen to reject, rather than explain, robust experimental findings of a role for sleep in memory and learning. In contrast, Nielsen has attempted to integrate conflicting findings in the dispute over REM versus NREM mentation. Researchers must trust the data more and the theories less, and build integrative rather than exclusionary models if they hope (...) to resolve these knotty problems effectively. [Nielsen; Vertes & Eastman]. (shrink)

The complexity and mysteriousness of mental processes during sleep rule out thinking only in term of generators. How could we know exactly what mental sleep experience (MSE) is produced and when? To refer to REM versus NREM as separate time windows for MSE seems insufficient. We propose that in each cycle NREM and REM interact to allow mentation to reach a certain degree of complexity and consolidation in memory. Each successive cycle within a sleep episode should (...) contribute to these processes with a different weight according to the time of night and distance from sleep onset. This view would avoid assuming too great a separation between REM and NREM functions and attributing psychological functions only to a single state. [Nielsen]. (shrink)

We present one of the first quantitative studies on auditory verbal experiences and auditory verbal agency voices or characters”) in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants’ implicit knowledge of auditory verbal experiences and auditory verbal agencies, displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement sleep, non-REM sleep, sleep onset, and waking. Physiology (...) was controlled with the nightcap sleep–wake mentation monitoring system. Sleep-onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic-pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. (shrink)

We present one of the first quantitative studies on auditory verbal experiences (“hearing voices”) and auditory verbal agency (inner speech, and specifically “talking to (imaginary) voices or characters”) in healthy participants across states of consciousness. Tools of quantitative linguistic analysis were used to measure participants’ implicit knowledge of auditory verbal experiences (VE) and auditory verbal agencies (VA), displayed in mentation reports from four different states. Analysis was conducted on a total of 569 mentation reports from rapid eye movement (...) (REM) sleep, non‐REM sleep, sleep onset, and waking. Physiology was controlled with the nightcap sleep–wake mentation monitoring system. Sleep‐onset hallucinations, traditionally at the focus of scientific attention on auditory verbal hallucinations, showed the lowest degree of VE and VA, whereas REM sleep showed the highest degrees. Degrees of different linguistic‐pragmatic aspects of VE and VA likewise depend on the physiological states. The quantity and pragmatics of VE and VA are a function of the physiologically distinct state of consciousness in which they are conceived. (shrink)

An ongoing assumption made by sleep researchers is that since dreams are more often recalled on awakening from rapid eye movement sleep, dreams must occur more often during this stage of sleep. An alternative hypothesis is that cognition occurs throughout sleep, but the recall of this mentation differs on awakening. When a dream is not reported on awakening, there is no method of establishing whether it did not happen or was forgotten. The aim of the (...) present study was to investigate this issue using an eye movement signal verification technique. Participants were instructed to produce an EM signal whenever they heard a tone. Tones were presented at increasing volume during Stage 2 and REM sleep until EM signal verification was observed. Ninety seconds after signal verification, participants were awakened and asked if they remembered hearing the tone or responding with the EM signal. Such recollection of signal verified tone presentations was significantly less after Stage 2 sleep compared to REM sleep presentations. Furthermore, SVT recall was significantly correlated with reported dream recall frequency, suggesting the same processes involved in recalling SVTs might also underlie dream recall. (shrink)

The approach of Hobson et al. is limited to the description of global states of consciousness, although more detailed analyses of the specific contents of consciousness would also be required. Furthermore, their account of the mind-brain relationship remains obscure. Nielsen's discussion suffers from conceptual and definitional unclarity. Mentation during sleep could be clarified by reconceptualizing it as an issue about the contents of consciousness. Vertes & Eastman do not consider the types of memory (emotional) and learning (implicit) that (...) are relevant during REM sleep, and therefore dismiss on inadequate grounds the possibility of memory functions associated with REM sleep. [Hobson et al.; Nielsen; Vertes & Eastman]. (shrink)

Nielsen's covert REM process model explains much of the mentation found in REM and NREM sleep, but stops short of postulating an interaction of waking cognitive processes with the dream mechanisms of REM sleep. It ranks with the Hobson et al. paper as a major theoretical advance. The Solms article does not surmount the ever-present problem of defining dreams in a manner conducive to advancing dream theory. Vertes & Eastman review the REM sleep and learning literature, (...) but make questionable assumptions in doing so. [Hobson et al.; Nielsen; Solms; Vertes & Eastman]. (shrink)

This paper examines the forms of life established through the visual governance of the Australian social security mobile app —the Express Plus Centrelink app. It is argued that the app exceeds established accounts of juridical and administrative power. The app involves a seeing that is not public, a responding that is not writing and a de-materialisation of an institution and its disciplinary apparatus. It is argued that the app creates proto-literate subjects that are required to respond to a real-time sequence (...) of images in a highly structured and circumscribed manner to become complicit in the digitalisation of their life. (shrink)

Traditionally, dream research focuses on accounting for typical psychological features of dream experiences characteristic of different sleep stages in terms of the global physiological features of the sleep stages in question. However, as subtle differences got into the forefront of enquiry, as, for example, in questions concerning between-stage similarities and within-stage differences of mentations, this methodology became insufficient. What recent findings and theoretical developments suggest is that understanding mental activity during sleep requires studying the fine-grained characteristics of (...) the phenomenal features of individual dreams, which, in turn, demands identifying specific neural processes that might underlie different characteristics of the experiences, and tracking their changes not just between but also within standard sleep stages. The paper argues that such a shift of focus from describing global stages to understanding the significance of local changes results in a true paradigm shift in dream research that can break away from the tradition of thinking about sleep mentation in terms of discrete categories, and offers a novel way of looking at dreams as forming a multidimensional continuum. (shrink)

Sleep researchers in different disciplines disagree about how fully dreaming can be explained in terms of brain physiology. Debate has focused on whether REM sleep dreaming is qualitatively different from nonREM (NREM) sleep and waking. A review of psychophysiological studies shows clear quantitative differences between REM and NREM mentation and between REM and waking mentation. Recent neuroimaging and neurophysiological studies also differentiate REM, NREM, and waking in features with phenomenological implications. Both evidence and theory suggest (...) that there are isomorphisms between the phenomenology and the physiology of dreams. We present a three-dimensional model with specific examples from normally and abnormally changing conscious states. Key Words: consciousness; dreaming; neuroimaging; neuromodulation; NREM; phenomenology; qualia; REM; sleep. (shrink)

Sleep researchers in different disciplines disagree about how fully dreaming can be explained in terms of brain physiology. Debate has focused on whether REM sleep dreaming is qualitatively different from nonREM (NREM) sleep and waking. A review of psychophysiological studies shows clear quantitative differences between REM and NREM mentation and between REM and waking mentation. Recent neuroimaging and neurophysiological studies also differentiate REM, NREM, and waking in features with phenomenological implications. Both evidence and theory suggest (...) that there are isomorphisms between the phenomenology and the physiology of dreams. We present a three-dimensional model with specific examples from normally and abnormally changing conscious states. Key Words: consciousness; dreaming; neuroimaging; neuromodulation; NREM; phenomenology; qualia; REM; sleep. (shrink)

Reinterpretation of our data concerning sleep onset, motivated by the desire to pay close attention to “intra-individual regularities,” suggests that the experience of control might be a key factor in determining the subjective sense that sleep has begun. This loss of control seems akin to what Frith and others have described as “passivity experiences,” which also occur in schizophrenia. Although clearly sleep onset is not a schizophrenic episode, this similarity might help to explain other features of (...) class='Hi'>sleep onset. We further speculate that we could build upon the discovery of various “intra-individual regularities” to construct a model of sleep onset and other forms of sleep mentation. (shrink)

Based on structural differences between spoken and written language, the purpose of this paper was to investigate whether spoken and written communication imply a different representation in reporting an experienced dream. In fact, the clausal-dynamic quality of the former and nominal-synoptic quality of the latter, with the consequent differences in length, cohesion and density, could enhance/reduce the perceptual character and narrative structure of report features often considered in order to assess sleep mentation. In particular, we wondered whether, after (...) eliminating all the elements responsible for the more conspicuous quantitative differences across the two forms , we would obtain two equivalent ways of reporting dreams. Three hundred and two subjects, raging in age from 18 to 40 years, participated as volunteers in the study and were asked to complete a dream diary daily for 14 days, by tape-recording their own dreams and putting them down in writing. The reports were analyzed by a psycholinguistic system. Results indicated that the report modality is able to affect the dream experience representation, conditioning the figurative translation carried out by the tester: written forms show a loss of hallucinatory information and a non-complete correspondence also of the bizarreness features with respect to the spoken texts. Partialling out for length eliminated any difference between spoken and written dream reports on bizarreness; on the other hand, controlling the sequence effect of the report did not introduce changes. Methodological and theoretical implications were discussed. (shrink)

Reflective waking mentation is supported by cortical activating and inhibitory processes. The thought-like mental content of slow wave sleep appears with lower levels of both kinds of influence. During REM sleep, the equation: activation + disinhibition + dopamine may explain the often psychotic-like mode of psychological functioning. [Hobson et al.; Nielsen; Revonsuo; Solms; Vertes & Eastman].

The continuous ongoing mentation is experienced as dreams in some functional states. Mentation occurs with high speed, is driven by individual memory, and uses state-dependent processing strategies, context material, storage options, and retrieval access. Retrieval deserves more attention. Multiple state-shifts owing to individual meaning as extracted also during sleep concatenate dream narratives and define access to segments for awake recall. [Hobson et al.; Nielson; Solms].

The studies reported in the following articles are aimed at providing a comprehensive, detailed, and quantitative picture of cognition in human dreaming. Our main premises are that waking, REM sleep, and non-REM sleep represent physiologically distinct and identifiable brain states and that the differences between waking, REM, and NREM mentation reflect these physiological differences. We have studied dreams at a formal level of analysis and, in these papers, have studied the specific dream properties of emotions, bizarre transformations, (...) scene shifts, and plot coherence, in adults and 4- to 10-year-old children, as part of a larger effort to map state-dependent mental phenomena back onto the varying neurobiological processes that must underlie them. We believe that such efforts will enhance our understanding not only of dreaming and its neurophysiological substrates, but also of the cognitive processes that dreaming shares with other unusual mental states. (shrink)

We have conducted a home-based study of children′s dream reports in which parents used open-ended interviewing styles to collect 88 dream reports from their 4- to 10-year-old children in the comfortable and supportive environment of their own homes. Particular attention was paid to formal properties including characters , settings, self-representation, and bizarreness. In contrast to previous studies, our data indicate that young children are able to give long, detailed reports of their dreams that share many formal characteristics with adult dream (...) reports. Because this wide range of dream mentation is only revealed to trusted confidants in a familiar and comfortable environment, an important implication is that the sleep laboratory may not be the best source of naturalistic dream data. (shrink)

Most current theoretical models of dreaming are built around an assumption that dream reports collected on awakening provide unbiased sampling of previous cognitive activity during sleep. However, such data are retrospective, requiring the recall of previous mental events from sleep on awakening. Thus, it is possible that dreaming occurs throughout sleep and differences in subsequent dream reports are owing to systematic differences in our ability to recall mentation on awakening. For this reason, it cannot be concluded (...) with certainty that sleep cognition is more predominant or in any way different during REM compared to NREM sleep. It is our contention that REM sleep and ponto-geniculo-occipital (PGO) waves do not necessarily represent stimulation of the cortex in the generation of dreams, but might rather represent enhanced arousal of attention mechanisms during sleep, which results in the subsequent recall of attended mentation on awakening. (shrink)

The relationship between dream content and waking life experiences remains difficult to decipher. However, some neurobiological findings suggest that dreaming can, at least in part, be considered epiphenomenal to ongoing memory consolidation processes in sleep. Both abnormalities in sleep architecture and impairment in memory consolidation mechanisms are thought to be involved in the development of psychosis. The objective of this study was to assess the continuity between delusional contents and dreams in acutely psychotic patients. Ten patients with a (...) single fixed and recurring delusional content were asked to report their dreams during an acute psychotic break. Sixteen judges with four different levels of acquaintance to the specific content of the patients’ delusions were asked to group the dreams, expecting that fragments of the delusional thought would guide the task. A mathematical index was developed in order to compare correct groupings between the four groups of judges. Most judges grouped the dreams slightly above chance level and no relevant differences could be found between the four groups [F = 1.297; p = n.s.]. Scoring of dreams for specific delusional themes suggested a continuity in terms of dream and waking mentation for two contents . These findings seem to suggest that at least some delusional contents recur within patients’ dreams. Future studies will need to determine whether such continuity reflects ongoing consolidation processes that are relevant to current theories of delusion formation and stabilization. (shrink)

Dreaming consciousness can be quite different from waking consciousness and this difference must depend upon the underlying neurobiology. Our approach is to infer the underlying brain basis for this difference by studying dream reports and comparing them with waking. In this study we investigated mentation during dreaming by asking subjects to provide us with dream reports and by asking them to create a dream log. In the dream log, the subjects recorded all implausibility, illogicality or inappropriateness of character during (...) the dream narrative when compared to the character’s real-life waking counterpart. Thus, the dream acted as its own control in comparing waking and dreaming mentation. (shrink)

We review the dream ESP studies conducted since the end of the Maimonides research programme. Combined effect size estimates for both sets of studies suggest that judges could correctly identify target materials more often than would be expected by chance using dream mentation. Maimonides studies were significantly more successful than post-Maimonides studies, which may be due to procedural differences, including that post-Maimonides receivers tended to sleep at home and were generally not deliberately awakened from REM sleep. Methodological (...) shortcomings of some studies are discussed. Nevertheless, home dream ESP research has been successful and continues to be a less expensive and less labour-intensive alternative to sleep-laboratory-based research. We hope that interest in dream ESP research will be re-awakened. (shrink)

A new philosophical analysis is provided of the notorious Sleeping Beauty Problem. It is argued that the correct solution is one-third, but not in the way previous philosophers have typically meant this. A modified version of the Problem demonstrates that neither self-locating information nor amnesia is relevant to the core Problem, which is simply to evaluate the conditional chance of heads given an undated Monday-or-Tuesday awakening. Previous commentators have failed to appreciate the significance of the information that Beauty gains upon (...) waking, and which is relevant to the conditional chance of heads: de re acquaintance with the awakening itself and the non-locating knowledge that it is an experimental awakening. David Lewis and company are committed to several unjustifiable and unacceptable probability assessments. Previous commentators have in effect confused the information that Beauty undergoes this particular experimental awakening for the information that she undergoes some experimental awakening or other. Lewis in particular thereby illegitimately tips the scales both in favor of heads and in favor of Monday. The Sleeping Beauty Problem is equivalent to a ball-in-urn word problem in elementary probability theory. (shrink)

What degrees of belief does Sleeping Beauty's evidence support? That depends.

Explores deep sleep (susupti), one of the three states of consciousness in Advaita Vedanta, and the major role it plays in this philosophy.

This paper examines three accounts of the sleeping beauty case: an account proposed by Adam Elga, an account proposed by David Lewis, and a third account defended in this paper. It provides two reasons for preferring the third account. First, this account does a good job of capturing the temporal continuity of our beliefs, while the accounts favored by Elga and Lewis do not. Second, Elga’s and Lewis’ treatments of the sleeping beauty case lead to highly counterintuitive consequences. The proposed (...) account also leads to counterintuitive consequences, but they’re not as bad as those of Elga’s account, and no worse than those of Lewis’ account. (shrink)

Adam Elga takes the Sleeping Beauty example to provide a counter-example to Reflection, since on Sunday Beauty assigns probability 1/2 to H, and she is certain that on Monday she will assign probability 1/3. I will show that there is a natural way for Bas van Fraassen to defend Reflection in the case of Sleeping Beauty, building on van Fraassen’s treatment of forgetting. This will allow me to identify a lacuna in Elga’s argument for 1/3. I will then argue, however, (...) that not all is well with Reflection: there is a problem with van Fraassen’s treatment of forgetting. Ultimately I will agree with Elga’s 1/3 answer. David Lewis maintains that the answer is 1/2; I will argue that cases of forgetting can be used to show that the premiss of Lewis’s argument for 1/2 is false. (shrink)

Terence Horgan defends the thirder position on the Sleeping Beauty problem, claiming that Beauty can, upon awakening during the experiment, engage in “synchronic Bayesian updating” on her knowledge that she is awake now in order to justify a 1/3 credence in heads. In a previous paper, I objected that epistemic probabilities are equivalent to rational degrees of belief given a possible epistemic situation and so the probability of Beauty’s indexical knowledge that she is awake now is necessarily 1, precluding such (...) updating. In response, Horgan maintains that the probability claims in his argument are to be taken, not as claims about possible rational degrees of belief, but rather as claims about “quantitative degrees of evidential support.” This paper argues that the most plausible account of quantitative degree of support, when conjoined with any of the three major accounts of indexical thought in such a way as to plausibly constrain rational credence, contradicts essential elements of Horgan’s argument. (shrink)

Cian Dorr (2002) gives an argument for the 1/3 position in Sleeping Beauty. I argue this is based on a mistake about Sleeping Beauty's epistemic position.

The strong law of large numbers and considerations concerning additional information strongly suggest that Beauty upon awakening has probability 1/3 to be in a heads-awakening but should still believe the probability that the coin landed heads in the Sunday toss to be 1/2. The problem is that she is in a heads-awakening if and only if the coin landed heads. So, how can she rationally assign different probabilities or credences to propositions she knows imply each other? This is the problem (...) I address in this article. I suggest that ‘p whenever q and vice versa’ may be consistent with p and q having different probabilities if one of them refers to a sample space containing ordinary possible worlds and the other to a sample space containing centred possible worlds, because such spaces may fail to combine into one composite probability space and, as a consequence, ‘whenever’ may not be well defined; such is the main contribution of this article. 1The Sleeping Beauty Game2Groisman’s and Peter Lewis’s Approaches3Discussing Beauty’s Credences4The Principle of Equivalence's Failure5Making Sense of the Principle of Equivalence's Failure6Elga’s and Lewis’s Approaches7ConclusionAppendix. (shrink)

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)