Comparing the phenomenology, neurochemical pathology, and psychopharmacology of hallucinations and dreaming is limited by the available data. Evidence to date reveals no simple correspondence between the two states. Differences in the phenomenology of visual hallucinations and the visual component of dreams may reflect variations in visual context acting on the same underlying mechanism – the minimal visual input during dreaming contrasts with the more substantial perceived context in hallucinations. Variations in cholinergic, dopaminergic and serotonergic neurotransmitter function during sleep and during (...) hallucinations in Lewy body dementias, together with relevant drug effects suggest that, on the whole, different, potentially opposite, changes characterise the two states. A similar analysis of other psychotic features in Lewy body dementia and other disorders suggests that, in contrast to hallucinations, there may be more convincing parallels between dreaming and delusional states. (shrink)

We critically review themushrooming literature addressing the neuralmechanisms of moral cognition (NMMC), reachingthe following broad conclusions: (1) researchmainly focuses on three inter-relatedcategories: the moral emotions, moral socialcognition, and abstract moral reasoning. (2)Research varies in terms of whether it deploysecologically valid or experimentallysimplified conceptions of moral cognition. Themore ecologically valid the experimentalregime, the broader the brain areas involved.(3) Much of the research depends on simplifyingassumptions about the domain of moral reasoningthat are motivated by the need to makeexperimental progress. This is a (...) valuablebeginning, but as more is understood about theneural mechanisms of decision-making, morerealistic conceptions will need to replace thesimplified conceptions. (4) The neuralcorrelates of real-life moral cognition areunlikely to consist in anything remotely like a``moral module'' or a ``morality center.'' Moralrepresentations, deliberations and decisionsare probably highly distributed and notconfined to any particular brainsub-system. Discovering the basic neuralprinciples governing planning, judgment anddecision-making will require vastly more basicresearch in neuroscience, but correlatingactivity in certain brain regions withwell-defined psychological conditions helpsguide neural level research. Progress on socialphenomena will also require theoreticalinnovation in understanding the brain'sdistinctly biological form of computationthat is anchored by emotions, needs, drives,and the instinct for survival. (shrink)

This article reviews recent findings indicating some common brain processes during dissociative states and dreaming with the aim to outline a perspective that neural chaotic states during dreaming can be closely related to dissociative states that may manifest in dreams scenery. These data are in agreement with various clinical findings that dissociated states can be projected into the “dream scenery” in REM sleep periods and dreams may represent their specific interactions that may uncover unusual psychological potential of creativity in psychotherapy, (...) art and scientific discoveries. (shrink)

I reject Lindquist et al.'s implicit claim that all emotion theories other than constructionist ones subscribe to a “brain locationist” 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 thespecificassumptions 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, thenatureof 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.

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

This research extends and confirms recent brainwave findings that distinguished an individual’s sense-of-self along an Object-referral/Self-referral Continuum of self-awareness. Subjects were interviewed and were given tests measuring inner/outer orientation, moral reasoning, anxiety, and personality. Scores on the psychological tests were factor analyzed. The first unrotated PCA component of the test scores yielded a “Consciousness Factor,” analogous to the intelligence “g” factor, which accounted for over half of the variance among groups. Analysis of unstructured interviews of these subjects revealed fundamentally different (...) descriptions of self-awareness. Individuals who described themselves in terms of concrete cognitive and behavioral processes exhibited lower Consciousness Factor scores, lower frontal EEG coherence, lower alpha and higher gamma power during tasks, and less efficient cortical preparatory responses . In contrast, individuals who described themselves in terms of an abstract, independent sense-of-self underlying thought, feeling and action exhibited higher Consciousness Factor scores, higher frontal coherence, higher alpha and lower gamma power during tasks, and more efficient cortical responses. These data suggest that definable states of brain activity and subjective experiences exist, in addition to waking, sleeping and dreaming, that may be operationally defined by psychological and physiological measures along a continuum of Object-referral/Self-referral Continuum of self-awareness. (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)

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)

Dreams are a remarkable experiment in psychology and neuroscience, conducted every night in every sleeping person. They show that the human brain, disconnected from the environment, can generate an entire world of conscious experiences by itself. Content analysis and developmental studies have promoted understanding of dream phenomenology. In parallel, brain lesion studies, functional imaging and neurophysiology have advanced current knowledge of the neural basis of dreaming. It is now possible to start integrating these two strands of research to address fundamental (...) questions that dreams pose for cognitive neuroscience: how conscious experiences in sleep relate to underlying brain activity; why the dreamer is largely disconnected from the environment; and whether dreaming is more closely related to mental imagery or to perception. (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)

REM sleep behaviour disorder is a REM sleep-related parasomnia which may be considered a “dissociated state of wakefulness and sleep”, given that conflicting elements of REM sleep and of wakefulness coexist during the episodes, leading to motor and behavioural manifestations reminiscent of an enacted dream. RBD has been reported in association with α-synucleinopathies: around a third of patients with Parkinson’s disease have full-blown RBD.Recent data indicate that PD patients with RBD are more prone to hallucinations than PD patients without this (...) parasomnia. However it is still not clear why RBD in PD is associated with an increased prevalence of VHs.Data exist which suggest that visual hallucinations in PD may be the result of untimely intrusions of REM visual imagery into wakefulness. RBD, which is characterised by a REM sleep dissociation pattern, might be a condition that particularly favours such intrusions. However, other hypotheses may be advanced. In fact, deficits in attentional, executive, visuoperceptual and visuospatial abilities have been documented in RBD and found to occur far more frequently in PD with RBD than in PD without RBD. Neuropsychological deficits involving visual perception and attentional processes are thought to play an important role in the pathophysiology of VHs. On this basis, RBD in PD could be viewed as a contributory risk factor for VHs. (shrink)

In addition to active wake, emotions are generated and experienced in a variety of functionally different states such as those of sleep, during which external stimulation and cognitive control are lacking. The neural basis of emotions can be specified by regarding the multitude of emotion-related brain states, as well as the distinct neuro- and psychodynamic stages (generation and regulation) of emotional experience.

Lucid dreaming refers to a dream state characterized by the dreamers awareness of being in a dream and being able to volitionally control its content. The aim of this study was to find neurophysiological evidence for the 7 criteria of lucid dreaming proposed by Paul Tholey. Each of the criteria was analyzed separately with regard to its underlying neurocircuits. We hypothesized that not one, but many regions are involved in the state of lucid dreaming. Our results have shown a satisfactory (...) overlap of the theoretical components and the brain regions activated during a lucid dream. During lucid dreaming, a brain network seems to emerge, that is more than the sum of its parts. Further research is needed to understand the psychoneurological underpinnings of lucid dreams. (shrink)

Why do we sleep? Loosing consciousness makes us completely vulnerable to any dangers of the environment for a third of our life time and must therefore yield a critical evolutionary advantage. A likely core function of sleep is the regulation of neuronal plasticity. The absence of interfering conscious information processing sets the stage for the basic maintenance of synaptic homeostasis to the complex reorganization and consolidation of memories. However, the underlying neuronal mechanisms subserving these processes are still largely unknown. The (...) aim of this thesis is to further elucidate the essential role of sleep-specific neuronal oscillations in brain plasticity. In a multimodal neuroscientific approach, non-invasive imaging methods (EEG and fMRI) and brain stimulation techniques (TMS and tDCS) are combined in a series of empirical studies to investigate how slow oscillations and sleep spindles are influenced by and in turn mediate plastic changes in the sleeping brain. (shrink)

Conscious perception, like the sight of a coffee cup, seems to involve the brain identifying a stimulus. But conscious input activates more brain regions than are needed to identify coffee cups and faces. It spreads beyond sensory cortex to frontoparietal association areas, which do not serve stimulus identification as such. What is the role of those regions? Parietal cortex support the ‘first person perspective’ on the visual world, unconsciously framing the visual object stream. Some prefrontal areas select and interpret conscious (...) events for executive control. Such functions can be viewed as properties of the subject, rather than the object, of experience – the ‘observing self’ that appears to be needed to maintain the conscious state. (shrink)