What is an altered state of consciousness?

How hypnotic suggestions work - A systematic review of prominent theories of hypnosis

In recent decades, hypnosis has increasingly moved into the mainstream of scientific inquiry. Hypnotic suggestions are frequently implemented in behavioral, neurocognitive, and clinical investigations and interventions. Despite abundant reports about the effectiveness of suggestions in altering behavior, perception, cognition, and agency, no consensus exists regarding the mechanisms driving these changes. This article reviews competing theoretical accounts that address the genesis of subjective, behavioral, and neurophysiological responses to hypnotic suggestions. We systematically analyze the broad landscape of hypnosis theories that best represent our estimation of the current status and future avenues of scientific thinking. We start with procedural descriptions of hypnosis, suggestions, and hypnotizability, followed by a comparative analysis of systematically selected theories. Considering that prominent theoretical perspectives emphasize different aspects of hypnosis, our review reveals that each perspective possesses salient strengths, limitations, and heuristic values. We highlight the necessity of revisiting extant theories and formulating novel evidence-based accounts of hypnosis.

EEG Microstate Dynamics Associated with Dream-Like Experiences During the Transition to Sleep

Consciousness always requires some representational content; that is, one can only be conscious about something. However, the presence of conscious experience (awareness) alone does not determine whether its content is in line with the external and physical world. Dreams, apart from certain forms of hallucinations, typically consist of non-veridical percepts, which are not recognized as false, but rather considered real. This type of experiences have been described as a state of dissociation between phenomenal and reflective awareness. Interestingly, during the transition to sleep, reflective awareness seems to break down before phenomenal awareness as conscious experience does not immediately fade with reduced wakefulness but is rather characterized by the occurrence of uncontrolled thinking and perceptual images, together with a reduced ability to recognize the internal origin of the experience. Relative deactivation of the frontoparietal and preserved activity in parieto-occipital networks has been suggested to account for dream-like experiences during the transition to sleep. We tested this hypothesis by investigating subjective reports of conscious experience and large-scale brain networks using EEG microstates in 45 healthy young subjects during the transition to sleep. We observed an inverse relationship between cognitive effects and physiological activation; dream-like experiences were associated with an increased presence of a microstate with sources in the superior and middle frontal gyrus and precuneus. Additionally, the presence of a microstate associated with higher-order visual areas was decreased. The observed inverse relationship might therefore indicate a disengagement of cognitive control systems that is mediated by specific, inhibitory EEG microstates.

The holistic effects of medical cannabis compared to opioids on pain experience in Finnish patients with chronic pain

BACKGROUND

Medical cannabis (MC) is increasingly used for chronic pain, but it is unclear how it aids in pain management. Previous literature suggests that MC could holistically alter the pain experience instead of only targeting pain intensity. However, this hypothesis has not been previously systematically tested.

METHOD

A retrospective internet survey was used in a sample of Finnish chronic pain patients (40 MC users and 161 opioid users). The patients evaluated statements describing positive and negative phenomenological effects of the medicine. The two groups were propensity score matched to control for possible confounding factors.

RESULTS

Exploratory factor analysis revealed three experience factors: Negative Side Effects, Positive Holistic Effects, and Positive Emotional Effects. The MC group (matched n = 39) received higher scores than the opioid group (matched n = 39) in Positive Emotional Effects with large effect size (Rank-Biserial Correlation RBC = .71, p < .001), and in Holistic Positive Effects with medium effect size (RBC = .47, p < .001), with no difference in Negative Side Effects (p = .13). MC and opioids were perceived as equally efficacious in reducing pain intensity. Ratings of individual statements were exploratively examined in a post hoc analysis.

CONCLUSION

MC and opioids were perceived to be equally efficacious in reducing pain intensity, but MC additionally positively affected broader pain-related factors such as emotion, functionality, and overall sense of wellbeing. This supports the hypothesis that MC alleviates pain through holistically altering the pain experience.

The claustrum and consciousness: An update

The seminal paper of Crick and Koch (2005) proposed that the claustrum, an enigmatic and thin grey matter structure that lies beside the insular cortex, may be involved in the processing of consciousness. As a result, this otherwise obscure structure has received ever-increasing interest in the search for neural correlates of consciousness. Here we review theories of consciousness and discuss the possible relationship between the claustrum and consciousness. We review relevant experimental evidence collected since the Crick and Koch (2005) paper and consider whether these findings support or contradict their hypothesis. We also explore how future experimental work can be designed to clarify how consciousness emerges from neural activity and to understand the role of the claustrum in consciousness.

Perturbations in dynamical models of whole-brain activity dissociate between the level and stability of consciousness

Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant information about a given state of consciousness. While the level of consciousness can be taken to describe the actual brain state, a complete characterization should also include its potential behavior against external perturbations. We developed and analyzed whole-brain computational models to show that the stability of conscious states provides information complementary to their similarity to conscious wakefulness. Our work leads to a novel methodological framework to sort out different brain states by their stability and reversibility, and illustrates its usefulness to dissociate between physiological (sleep), pathological (brain-injured patients), and pharmacologically-induced (anesthesia) loss of consciousness.

Comparative effects of (S)-ketamine and racemic (R/S)-ketamine on psychopathology, state of consciousness and neurocognitive performance in healthy volunteers

Ketamine and its (S)-enantiomer show distinct psychological effects that are investigated in psychiatric research. Its antidepressant activity may depend on the extent and quality of these psychological effects which may greatly differ between the enantiomers. Previous data indicate that the (S)-ketamine isomer is a more potent anesthetic than (R)-ketamine. In contrast, in subanesthetic doses (R)-ketamine seems to elicit fewer dissociative and psychotomimetic effects compared to (S)-ketamine. In this randomized double-blind placebo-controlled trial the effects of (R/S)-ketamine and (S)-ketamine on standardized neuropsychological and psychopathological measures were compared. After an initial bolus equipotent subanesthetic doses of (R/S)- and (S)-ketamine or placebo were given by continuous intravenous infusion to three groups of 10 healthy male volunteers each (n = 30). (R/S)-Ketamine and (S)-ketamine produced significant psychopathology and neurocognitive impairment compared to placebo. No significant differences were found between (R/S)-ketamine and (S)-ketamine. (S)-Ketamine administration did not result in reduced psychopathological symptomatology compared to (R/S)-ketamine as suggested by previous studies. However, this study revealed a somewhat more "negatively experienced" psychopathology with (S)-ketamine, which opens questions about potential "protective effects" associated with the (R)-enantiomer against some psychotomimetic effects induced by the (S)-enantiomer. As the antidepressant effect of ketamine might depend on a pleasant experience of altered consciousness and perceptions and avoidance of anxiety, the ideal ketamine composition to treat depression should include (R)-ketamine. Moreover, since preclinical data indicate that (R)-ketamine is a more potent and longer acting antidepressant compared to (S)-ketamine and (R/S)-ketamine, randomized controlled trials on (R)-ketamine and comparative studies with (S)-ketamine and (R/S)-ketamine are eagerly awaited.

Bridging the Gap? Altered Thalamocortical Connectivity in Psychotic and Psychedelic States

Psychiatry has a well-established tradition of comparing drug-induced experiences to psychotic symptoms, based on shared phenomena such as altered perceptions. The present review focuses on experiences induced by classic psychedelics, which are substances capable of eliciting powerful psychoactive effects, characterized by distortions/alterations of several neurocognitive processes (e.g., hallucinations). Herein we refer to such experiences as psychedelic states. Psychosis is a clinical syndrome defined by impaired reality testing, also characterized by impaired neurocognitive processes (e.g., hallucinations and delusions). In this review we refer to acute phases of psychotic disorders as psychotic states. Neuropharmacological investigations have begun to characterize the neurobiological mechanisms underpinning the shared and distinct neurophysiological changes observed in psychedelic and psychotic states. Mounting evidence indicates changes in thalamic filtering, along with disturbances in cortico-striato-pallido-thalamo-cortical (CSPTC)-circuitry, in both altered states. Notably, alterations in thalamocortical functional connectivity were reported by functional magnetic resonance imaging (fMRI) studies. Thalamocortical dysconnectivity and its clinical relevance are well-characterized in psychotic states, particularly in schizophrenia research. Specifically, studies report hyperconnectivity between the thalamus and sensorimotor cortices and hypoconnectivity between the thalamus and prefrontal cortices, associated with patients' psychotic symptoms and cognitive disturbances, respectively. Intriguingly, studies also report hyperconnectivity between the thalamus and sensorimotor cortices in psychedelic states, correlating with altered visual and auditory perceptions. Taken together, the two altered states appear to share clinically and functionally relevant dysconnectivity patterns. In this review we discuss recent findings of thalamocortical dysconnectivity, its putative extension to CSPTC circuitry, along with its clinical implications and future directions.

Whole-Brain Models to Explore Altered States of Consciousness from the Bottom Up

The scope of human consciousness includes states departing from what most of us experience as ordinary wakefulness. These altered states of consciousness constitute a prime opportunity to study how global changes in brain activity relate to different varieties of subjective experience. We consider the problem of explaining how global signatures of altered consciousness arise from the interplay between large-scale connectivity and local dynamical rules that can be traced to known properties of neural tissue. For this purpose, we advocate a research program aimed at bridging the gap between bottom-up generative models of whole-brain activity and the top-down signatures proposed by theories of consciousness. Throughout this paper, we define altered states of consciousness, discuss relevant signatures of consciousness observed in brain activity, and introduce whole-brain models to explore the biophysics of altered consciousness from the bottom-up. We discuss the potential of our proposal in view of the current state of the art, give specific examples of how this research agenda might play out, and emphasize how a systematic investigation of altered states of consciousness via bottom-up modeling may help us better understand the biophysical, informational, and dynamical underpinnings of consciousness.

Alteration of consciousness in Ancient Greece: divine mania

Ancient Greece was unique in its attitude to alteration of consciousness. Various altered states of consciousness were commonly known: initiates experienced them during mystery rites; sacred officials and enquirers attained them in the major oracular centres; possession by various deities was recognized; and some sages and philosophers practised manipulation of consciousness. From the perspective of individual and public freedom, the prominent position of mania in Greek society reflects its openness and acceptance of the inborn human proclivity to experience alterations of consciousness, which were interpreted in positive terms as god-sent. These mental states were treated with cautious respect, but never suppressed or pushed to the cultural and social periphery, in contrast to many other complex societies, ancient and modern.

A Deep-Dream Virtual Reality Platform for Studying Altered Perceptual Phenomenology

Altered states of consciousness, such as psychotic or pharmacologically-induced hallucinations, provide a unique opportunity to examine the mechanisms underlying conscious perception. However, the phenomenological properties of these states are difficult to isolate experimentally from other, more general physiological and cognitive effects of psychoactive substances or psychopathological conditions. Thus, simulating phenomenological aspects of altered states in the absence of these other more general effects provides an important experimental tool for consciousness science and psychiatry. Here we describe such a tool, which we call the Hallucination Machine. It comprises a novel combination of two powerful technologies: deep convolutional neural networks (DCNNs) and panoramic videos of natural scenes, viewed immersively through a head-mounted display (panoramic VR). By doing this, we are able to simulate visual hallucinatory experiences in a biologically plausible and ecologically valid way. Two experiments illustrate potential applications of the Hallucination Machine. First, we show that the system induces visual phenomenology qualitatively similar to classical psychedelics. In a second experiment, we find that simulated hallucinations do not evoke the temporal distortion commonly associated with altered states. Overall, the Hallucination Machine offers a valuable new technique for simulating altered phenomenology without directly altering the underlying neurophysiology.

Hypnotic susceptibility and affective states in bipolar I and II disorders

BACKGROUND

Highly hypnotizable individuals have impaired executive function, elevated motor impulsivity and increased emotional sensitivity, which are sometimes found in bipolar disorder patients. It is then reasonable to assume that certain aspects of hypnotic susceptibility differ with the types of bipolar disorder.

METHODS

The Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C) test, the Mood Disorder Questionnaire (MDQ), the Hypomanic Checklist-32 (HCL-32) and the Plutchick-van Praag Depression Inventory (PVP) were applied to 62 patients with bipolar I disorder, 33 bipolar II disorder, and 120 healthy volunteers.

RESULTS

The passing rate of the SHSS:C 'Moving hands apart' item was higher in bipolar I patients than in controls, whereas for 'Mosquito hallucination' the rate was lower. Bipolar I and II patients scored significantly higher on MDQ, HCL-32 and PVP scales than controls. The passing rates of 'Mosquito hallucination' in controls, 'Arm rigidity' in bipolar I, and 'Age regression' in bipolar II predicted the respective MDQ scores.

CONCLUSION

In contrast to cognitive suggestions, bipolar I patients followed motor suggestions more often under hypnosis. Furthermore, both bipolar disorder patients and healthy volunteers demonstrated associations between mania levels and certain hypnotic susceptibility features. Our study aids in better understanding the altered conscious states in bipolar disorders, and encourages the use of related psychotherapy for these patients.

Educated Guesses and Other Ways to Address the Pharmacological Uncertainty of Designer Drugs: An Exploratory Study of Experimentation Through an Online Drug Forum

This study examines how experimentation with designer drugs is mediated by the Internet. We selected a popular drug forum that presents reports on self-experimentation with little or even completely unexplored designer drugs to examine: (1) how participants report their "trying out" of new compounds and (2) how participants reduce the pharmacological uncertainty associated with using these substances. Our methods included passive observation online, engaging more actively with the online community using an avatar, and off-line interviews with key interlocutors to validate our online findings. This article reflects on how forum participants experiment with designer drugs, their trust in suppliers and the testimonials of others, the use of ethno-scientific techniques that involve numerical weighing, "allergy dosing," and the use of standardized trip reports. We suggest that these techniques contribute to a sense of control in the face of the possible toxicity of unknown or little-known designer drugs. The online reporting of effects allows users to experience not only the thrill of a new kind of high but also connection with others in the self-experimenting drug community.

Clinical hypnosis and Patanjali yoga sutras

The trance states in yoga and hypnosis are associated with similar phenomena like relaxation, disinclination to talk, unreality, misrepresentation, alterations in perception, increased concentration, suspension of normal reality testing, and the temporary nature of the phenomena. While some researchers consider yoga to be a form of hypnosis, others note that there are many similarities between the trance in yoga and the hypnotic trance. The present study aimed to find similarities between the trance states of hypnosis and Patanjali's yoga sutras. The trance states were compared with the understanding of the phenomena of trance, and the therapeutic techniques and benefits of both. An understanding of the concept of trance in Patanjali's yoga sutras was gained through a thematic analysis of the book Four Chapters on Freedom by Swami Satyananda Saraswati. This led to an understanding of the concept of trance in the yoga sutras. The obtained concepts were compared to the concepts of trance in hypnosis (obtained through the literature on hypnosis) to investigate whether or not there exist similarities. The findings of the study show that there are similarities between the trance in hypnosis and the trance in Patanjali's yoga sutras in the induction and deepening of the trance states in hypnosis and that of Samadhi, the phenomena present in hypnosis and the kinds of siddhis that are obtained through Samadhi, and the therapeutic techniques and the therapeutic process in Patanjali's yoga sutra and hypnosis.

Pretend play and development in early childhood (with implications for the oedipal phase)

Pretend play reflects both the unique mental organization and the developmental challenges of early to middle childhood, with a trajectory that parallels the monumental transformation of the toddler to the school-age child. Despite evidence for various forms of playing throughout the life cycle, the flowering of symbolic play in this phase is specific, essential, and typically transient in terms of its dominance in the life of the child. It reflects the simultaneous emergence, processing, and integration of the remarkable developmental advances occurring during this period, most especially the capacity to symbolize, in the service of the exponentially expanded psychosexual/social/emotional force field implied in the contemporary use of the term oedipus complex. Moreover, it constitutes a particular mental organization and ego state, with idiosyncratic mentation, affect regulation, and relationship to inner and outer experience, that accompanies the child's gradual orientation to consensual reality. Subsequent access to some form of this state varies widely among individuals but is rarely fully comparable.

The experience of altered states of consciousness in shamanic ritual: the role of pre-existing beliefs and affective factors

Much attention has been paid recently to the role of anomalous experiences in the aetiology of certain types of psychopathology, e.g. in the formation of delusions. We examine, instead, the top-down influence of pre-existing beliefs and affective factors in shaping an individual's characterisation of anomalous sensory experiences. Specifically we investigated the effects of paranormal beliefs and alexithymia in determining the intensity and quality of an altered state of consciousness (ASC). Fifty five participants took part in a sweat lodge ceremony, a traditional shamanic ritual which was unfamiliar to them. Participants reported significant alterations in their state of consciousness, quantified using the 'APZ' questionnaire, a standardized measure of ASC experience. Participants endorsing paranormal beliefs compatible with shamanic mythology, and those showing difficulty identifying feelings scored higher on positive dimensions of ASC experience. Our findings demonstrate that variation in an individual's characterisation of anomalous experiences is nuanced by pre-existing beliefs and affective factors.