Medical hypotheses
January 1, 2006
U Maas, S Strubelt
41 citations
Ibogaine, the main alkaloid of the Central African Iboga shrub, is used in Gabonian initiation ceremonies to induce near-death experiences and in Western clinics for addiction treatment, but it is illegal in the US and most of Europe because at least eight people have died after taking it, often days later or from very small doses. The authors hypothesize that these deaths result from cardiac arrhythmias caused by autonomic nervous system dysregulation. Small doses stimulate the sympathetic system (fight or flight), while high doses cause vagal dominance (feigned death).
Medical hypotheses
November 1, 2020
Michael Raduga, Oleg Kuyava, Natalia Sevcenko
31 citations
During REM sleep, people normally dream, but some also experience lucid dreaming (being conscious during a dream), false awakening (dreaming that one has woken up), sleep paralysis (temporary muscle atonia upon waking or falling asleep), and out-of-body experiences (the sensation of leaving the physical body). A survey of 974 people on the streets of Moscow found that 88% had experienced at least one of these phenomena, and 43% experienced one often. These phenomena were closely correlated with each other, and their recurrence correlated with sleep duration and dream recall frequency. The results suggest these REM sleep dissociative phenomena are interconnected.
Medical hypotheses
January 1, 2021
Timothy D Brewerton, Adele Lafrance, Michael C Mithoefer
28 citations
Eating disorders remain difficult to treat, especially when accompanied by posttraumatic stress disorder. MDMA-assisted psychotherapy for treatment-resistant PTSD shows promise, with two-thirds of participants achieving full remission at one year or more follow-up. The authors hypothesize this therapy will be effective for both eating disorder and PTSD symptoms in people with both conditions. MDMA's effects—reduced fear, enhanced wellbeing, increased sociability, reduced self-criticism, increased compassion, interpersonal trust, and alert consciousness—may counteract avoidance and hyperarousal in therapy. Other features like body image distortion, cognitive rigidity, and socio-emotional difficulties may also improve. Personal accounts describe benefit, but risks and challenges are noted.
Medical hypotheses
March 11, 2020
J S Torday
16 citations
Consciousness is proposed to be a product of the Singularity/Big Bang, arising from the internalization of environmental factors that shaped human physiology. This view requires that consciousness diachronically cuts across space-time and operates on the same data system as cosmology. By recognizing this mechanistic interrelationship, humans can transcend individual consciousness and approach a universal Consciousness by authoring their own software. The hypothesis argues that previous explanations, from Plato to Descartes and Chalmers, lack empirical evidence for what consciousness actually constitutes.
Medical hypotheses
September 1, 2019
Enrico Facco, Laura Mendozzi, Angelo Bona et al.
16 citations
Five individuals with unusual hypnotic ability, free of psychiatric disorders, spontaneously experienced multiple identities during hypnosis, which they later did not recall due to post-hypnotic amnesia. Brain scans showed reduced connectivity in the Default Mode Network, particularly between the posterior cingulate cortex and medial prefrontal cortex. Comparing these findings with fMRI data from Dissociative Identity Disorder patients suggests a continuum between normal mental functioning, where multiple identities can coexist unconsciously, and pathological dissociation. The authors argue that a sharp boundary between normal and pathological experiences may be artificial, and that non-ordinary mental expressions like these should be understood rather than treated.
Medical hypotheses
January 1, 2007
Bruce G Charlton
15 citations
Alienation, the feeling that life is meaningless and that we do not belong, is not inevitable. Animistic thinking, which regards significant entities as sentient agents with minds, is the natural and spontaneous human worldview, shared by children and hunter-gatherers. This thinking embeds humans in a world of social relationships with animals, plants, and landscapes. Formal education overwrites animism with rationalistic objectivity, creating alienation by estranging people from a relational world. Recovering animistic thinking involves detachment from social systems that enforce objectivity—through solitude, leisure, nature contact, or altered states of consciousness such as meditation, lucid dreaming, trance states, or intoxication. Intoxication, however, impairs memory and can be dangerous, yet seeking altered states remains a major spiritual practice.
Medical hypotheses
December 1, 2008
Bruce G Charlton
12 citations
Genetic engineering could be used to enhance human spiritual and religious experiences, a concept termed 'genospirituality'. If technologies safely engineer genes linked to spiritual behaviors, people might choose their degree of religiosity, potentially increasing direct religious experiences like revelation, animistic thinking where natural features are seen as sentient, or shamanistic states of altered consciousness that can be self-induced and switched off. Trade-offs may include reduced drive for status and monetary rewards, but also more altruistic, moral behaviors and strengthened communal joy. Genospirituality would likely appeal to those unable to achieve desired spiritual experiences.
Medical hypotheses
February 1, 2016
Thomas S Ray
6 citations
MDMA (ecstasy) produces a distinct open-hearted mental state that defines the drug class 'entactogens'. While consensus holds that this state arises from neurotransmitter release, primarily serotonin, an alternative hypothesis proposes simultaneous direct activation of imidazoline-1 (I1) and serotonin-2 (5-HT2) receptors. This hypothesis is grounded in 'mental organ' theory, where mental organs are neuron populations expressing a defining metabotropic receptor, each playing an evolutionarily shaped role in the mind. For a mental organ to enter consciousness, it must be directly activated at its receptor, 5-HT2 must be co-activated, and 5-HT2 activation loads the organ into consciousness.
Medical hypotheses
January 1, 1986
T Riedlinger, J Riedlinger
5 citations
Birth trauma theories, particularly Stanislav Grof's, have been dismissed by mainstream psychology due to lack of evidence and assumptions about neonatal brain development. However, evidence from over 3,500 psychedelic-assisted psychotherapy sessions suggests a link between unconscious birth trauma memories and mental conditions. Research on psychedelic effects, subcortical learning, and emotional response offers explanations that address Freud's objections without refuting them. This review concludes that birth trauma theories deserve more serious consideration from mainstream psychologists and medical researchers.
Medical hypotheses
March 1, 2017
Grzegorz R Juszczak
4 citations
LSD, a model psychedelic, triggers sensory experiences such as illusory movement, floating, merging with surroundings, and out-of-body experiences. While the molecular action at 5-HT2a receptors is known, how these lead to specific sensations is unclear. The authors propose that LSD disrupts the integration of sensory input with information about the body's movement, as serotonergic neurons normally convey motor activity and orienting responses. This disruption results in the perception of illusory movement attributed to the self or external objects.
Medical hypotheses
November 1, 2013
E Maciejczyk, P Kafarski
4 citations
Mannitol, abundant in the tissues of the fly agaric mushroom (Amanita muscaria), may facilitate the transport of the mushroom's active compounds into the brain, thereby enhancing their overall psychoactive effects. This hypothesis is supported by the observation that the hallucinogenic effect from consuming the whole mushroom is greater than what would be expected from the quantity of active substances it contains, suggesting that mannitol acts as a co-factor that improves brain penetration and potency.
Medical hypotheses
October 1, 2020
E S Lansky
1 citation
The eye contains serotonin and its receptors, and drugs that bind to these receptors may affect vision. Selective serotonin reuptake inhibitors (SSRIs) can impair ocular function, while other serotonin-binding drugs might improve it. Harmine, a naturally occurring alkaloid found in plants such as Passiflora, Peganum, and Banisteriopsis, is proposed as a candidate for improving vision. At individualized low doses, these plants are minimally hallucinogenic and well tolerated, with potential long-lasting benefits from one or few administrations. The hypothesized mechanism involves tuning serotonergic receptors in the eye. Blinded research with harmala alkaloid-containing plants, using psychedelic therapy methods, could assess visual acuity in presbyopia.
Medical hypotheses
March 1, 2021
Baland Jalal
Sleep paralysis is a condition in which a person, while paralyzed, may hallucinate terrifying ghosts—often faceless shadows, but also full figures like cat-like creatures or witches. This paper proposes a neuroscientific account explaining why these hallucinations occur and why they typically appear as faceless shadows. The account focuses on the distinct computational styles of the right and left hemispheres, suggesting that ghost hallucinations and out-of-body experiences during sleep paralysis are primarily mediated by activity in key right-hemisphere regions. The visual system's economizing nature, including surface interpolation and shortcuts, is invoked to explain faceless humanoid-shadows and sensed presence. The hypothalamus and anterior cingulate may also be involved in related dissociative states. The author notes that empirical research is needed to validate this hypothesis.
Medical hypotheses
April 1, 2019
Fredric Schiffer
Subjectivity—the first-person quality of experience—remains unexplained by neuroscience, which only describes its neural correlates. A hypothesis is proposed that undiscovered quantum fields, distinct from known fields, induce subjectivity when they interact with specific brain information. These fields would emit quantum particles that exert force on brain patterns conveying meaning, thereby generating experience. Most experience is non-conscious, continuously informing brain structure and behavior, while only intermittently becoming conscious. The article explores how non-conscious experience relates to the self and how it may become conscious, offering support and directions for testing this hypothesis, along with potential clinical applications in psychology.
Medical hypotheses
April 1, 2017
Lucio Tonello, Massimo Cocchi, Fabio Gabrielli et al.
Mainstream neuropsychiatry faces limitations, and quantum theories of mind, brain, and consciousness offer a paradigm shift but lack experimental support and deviate radically from current views. A proposal integrates experimental neuroscience with quantum models by linking the stream of consciousness to Gamma Synchrony (GS) observed in EEG data. In this framework, unipolar depression may involve an altered stream of consciousness with increased power. This approach could extend to psychopathology generally, potentially improving diagnostics and therapeutics in neuropsychiatry.
Medical hypotheses
September 1, 2016
Stephen L Thaler
A theoretical paper proposes that the brain's creative process mirrors the behavior of two interacting artificial neural networks, where one generates random activation patterns (ideas) and the other evaluates them. The system cycles between high synaptic perturbation (chaos, idea incubation) and low perturbation (stability, idea reinforcement). Volume neurotransmitter release in the cortex is proposed as the biological source of these fluctuations, affecting both generative and evaluative networks. The authors hypothesize that creativity and certain psychopathologies share the same underlying neurodynamics, with extremes in the chaotic phase being problematic. This theory suggests that controlling the balance of excitatory and inhibitory neurotransmitters could potentially boost creativity or treat related disorders.
Medical hypotheses
February 1, 2016
Ming-Chyi Huang, Lian-Yu Chen, Chih-Ken Chen et al.
Ketamine, a derivative of phencyclidine (PCP), has dissociative, analgesic, and psychedelic properties and is increasingly used recreationally. Preclinical studies show its reinforcing effects and that long-term abuse leads to delayed, persistent upregulation of the dopamine system. Concerns exist about its addiction liability, but no effective pharmacotherapy is available for treatment-seeking abusers. Limited evidence suggests lamotrigine, which inhibits glutamate release, reduces cocaine craving. The authors propose lamotrigine may help manage ketamine use disorder and report one case where craving and use greatly reduced after taking lamotrigine. Future clinical trials are needed to understand lamotrigine's benefits.
Medical hypotheses
December 1, 2013
James M Robertson
Consciousness and explicit memory storage may depend on a three-dimensional matrix formed by protoplasmic astrocytes in the brain. Recent anatomical and physiological evidence shows that individual astrocytes occupy separate, non-overlapping tessellating domains that tile cortical gray matter. Each domain encompasses many thousands of synapses, and astrocytes respond to neural activity as rapidly as neurons do, distinguishing inputs from different pathways. Astrocytes in sensory cortex can discriminate sensory details more finely than surrounding neurons. Domains are interconnected by gap junctions, forming syncytial networks that may extend across the entire neocortex. This matrix is proposed to seamlessly bind attended sensory information and encode explicit memories, with the temporal stream of consciousness arising from sequential neural activity.
Medical hypotheses
July 1, 2013
M Coppola, R Mondola
Methoxydine, a dissociative anaesthetic in the arylcyclohexylamine class, pharmacodynamically resembles ketamine, a known rapid-acting antidepressant. Binding assays indicate it is an uncompetitive NMDA receptor antagonist about as potent as ketamine but less potent than PCP. Unlike ketamine, methoxydine also inhibits reuptake of dopamine, serotonin, and noradrenaline and acts as an agonist at sigma-1, sigma-2, and opioid receptors. The hypothesis is that methoxydine could produce rapid antidepressant effects in depressed patients at high risk of suicide, including depressed alcoholics.
Medical hypotheses
May 1, 2010
Brian Milne
Electroconvulsive therapy (ECT) is widely used for psychiatric conditions but has side effects including memory loss, injury, arrhythmias, and risks from anesthesia. Nitrous oxide (laughing gas) is proposed as a potential substitute because it shares some effects with ECT: it induces laughter (described as nature's epileptoid catharsis), produces central sympathetic stimulation, releases endogenous opioid peptides that may have antidepressant properties, and can trigger seizure-like activity. The author argues that nitrous oxide is relatively safe, easy to administer, and could be given in a series of treatments similar to ECT, making it a feasible alternative.
Medical hypotheses
January 1, 2005
Shahar Arzy, Moshé Idel, Théodor Landis et al.
Revelation experiences foundational to the three monotheistic religions share phenomenological features with experiences reported by contemporary non-mystic mountaineers at altitude, including feeling and hearing a presence, seeing a figure or lights, and fear. The authors suggest that exposure to altitude may alter functional and neural mechanisms—particularly in the temporo-parietal junction and prefrontal cortex—that facilitate such experiences. Acute and chronic hypoxia affect these brain areas, which are also linked to altered body perceptions and mystical experiences. Prolonged high-altitude stays, especially with social deprivation, may cause prefrontal lobe dysfunctions like reduced stress resistance and loss of inhibition. These parallels indicate altitude exposure might contribute to inducing revelation experiences and help explain the mountain metaphor in religion.
Medical hypotheses
April 1, 2002
M Fritzsche
Schizophrenia, cannabis intoxication, and cannabis psychosis produce similar distortions in time and space perception, suggesting a shared underlying dysfunction. Rather than pursuing genetic research, which has yielded disappointing results, this study examines information-theoretic explanations for these psychotic states. The authors propose that in acute psychosis, Kolmogorov entropy—involved in processing action and time—breaks down, while Shannon entropy—involved in higher-dimensional perception—increases, leading to positive symptoms and altered consciousness. Non-linear EEG analysis of Kolmogorov information could become a diagnostic tool for assessing information-processing breakdown in schizophrenia and help identify vulnerable individuals for protection against cannabis abuse.