Content uploaded by Peter Brugger
Author content
All content in this area was uploaded by Peter Brugger
Content may be subject to copyright.
Abstract
This study attempted a systematic investigation of incidence, type, and circumstances of anomalous perceptual experiences in a highly specialized group of healthy subjects, extreme-altitude climbers.
There is anecdotal evidence for a high incidence of anomalous perceptual experiences during mountain climbing at high altitudes.
In a structured interview, we asked eight world-class climbers, each of whom has reached altitudes above 8500 m without supplementary oxygen, about hallucinatory experiences during mountain climbing at various altitudes. A comprehensive neuropsychological, electroencephalographic, and magnetic resonance imaging evaluation was performed within a week of the interview (8).
All but one subject reported somesthetic illusions (distortions of body scheme) as well as visual and auditory pseudohallucinations (in this order of frequency of occurrence). A disproportionately large number of experiences above 6000 m as compared to below 6000 m were reported (relative to the total time spent at these different altitudes). Solo climbing and (in the case of somesthetic illusions) life-threatening danger were identified as probable triggers for anomalous perceptual experiences. No relationship between the number of reported experiences and neuropsychological impairment was found. Abnormalities in electroencephalographic (3 climbers) and magnetic resonance imaging (2 climbers) findings were likewise unrelated to the frequency of reported hallucinatory experiences.
The results confirm earlier anecdotal evidence for a considerable incidence of hallucinatory experiences during climbing at high altitudes. Apart from hypoxia, social deprivation and acute stress seem to play a role in the genesis of these experiences.
... Autoscopic phenomena (AP) are illusory multisensory own body reduplications that occur in various neuropsychiatric conditions and the healthy population (Brugger et al., 1999;Devinsky et al., 1989;Hécaen and Ajuriaguerra, 1952). AP are characterized by the illusory visual perception of one's own body in extrapersonal space, are classified among disorders of the body schema (Devinsky et al., 1989;Brugger and Landis, 1997) and have recently been the target of neuroscientific investigations due to their relevance for self and self-consciousness and related multisensory processing (Blanke, 2012). ...
... Moreover, the number of tested patients remained low and AP occur in many different patient populations (Devinsky et al., 1989;Blanke et al., 2004;Ionta et al., 2011), some of which are not associated with focal brain damage, several cases have been linked to epilepsy, compatible with propagation of ictal activity within more extended networks. Based on these findings we hypothesized that AP may be associated with alterations in functional brain connectivity as measured by fMRI (Brugger et al., 1999;Hécaen and Ajuriaguerra, 1952). Lesion network analysis may uncover brain networks associated with specific neurological symptoms (Boes et al., 2015) and allows to determine whether heterogeneously distributed lesions causing the same symptom are part of the same network. ...
Objective
Autoscopic phenomena (AP) are illusory own body reduplications characterized by the visual perception of a second own body in extrapersonal space, and include three main forms: autoscopic hallucination (AH), heautoscopy (HAS) and out-of-body-experience (OBE). Past research showed that lesions were heterogeneously distributed and affected many different brain regions within and across patients, while small case series suggested that AP lesions converge in temporo-parietal and parieto-occipital cortex. As only few studies investigated each form of AP separately, it remains unknown whether the three AP are characterized by common and distinct brain mechanisms.
Methods
Here, we applied lesion network analysis in 26 neurological AP patients and determined their common and distinct functional connectivity patterns.
Results
We report that all localize to a single common brain network at the bilateral temporo-parietal junction, further associated with specific patterns of functional connectivity, defining each type of AP. OBE resulted from a brain network connected to bilateral angular gyrus, right precuneus, and right inferior frontal gyrus, differing from AH with a brain network connected to bilateral precuneus, inferior temporal gyrus, and cerebellum. HAS resulted from a brain network connected to left inferior frontal gyrus, left insula and left parahippocampus.
Conclusion
The present data identify the temporo-parietal junction as the common core region for AP and show that each form of AP recruits additional specific networks, associated with different sensorimotor and self-related sub-networks.
... Two studies (Bassi & Delle Fave, 2010;Delle Fave et al., 2003) were classified as one sample as data were for the same participants on the same expedition. Likewise, samples in two studies that involved the same participants (Brugger et al., 1999;Regard et al., 1989) were classified as an independent sample. The most common reason for exclusion (78.57%; k = 66) was that participants did not meet our definition of mountaineers, while data in five included articles were also omitted due to ineligibility (see Supplemental data 5 for exclusion reasons). ...
... The sensitivity analysis (see Supplemental data 9) indicated that the majority of codes in the synthesis (91%) sourced data from three or more studies, with only four codes developed based on data from two studies. Four studies included in the review (Brugger et al., 1999;Burnik et al., 2002;Gürer, 2015;Missoum et al., 1992) did not feature in the synthesis as codes generated in these studies did not translate to any other study. Eighteen studies in the synthesis contributed to a single code, with the majority (k = 30) featured in 2-5 codes. ...
Research on the psychology of mountaineering has received widespread attention over many decades. Therefore, to clarify scientific findings in the area, provide future research directions, and enable the development of applied recommendations to enhance performance and safety, the purpose of this systematic mixed studies review was to identify, appraise, and synthesise research on the psychology of mountaineering. After systematically searching 10 electronic databases and undertaking manual searches up to April 2020, 69 studies published over 54 years (1966–2020) were included in the review. Thematic synthesis was undertaken and generated 11 descriptive themes, which were captured by two analytical themes, (i) personality characteristics of mountaineers, and (ii) psychological experiences in mountaineering. The synthesis generated novel insights into connections between different research topics in the psychology-specific literature in mountaineering, thus providing a more advanced understanding of current knowledge in this area. The review highlights that considerable progress has been made in this field, but further high-quality studies are required across all facets of this literature. Future avenues for research include: group dynamics; cognitive mechanisms underlying decision-making; and coping with setbacks and traumatic events.
... The neurological basis of SenP has long been established from case studies of epilepsy [59][60][61][62], Parkinson's disease [63], migraine [64], and hypoxia [65]. More recently, neuroimaging and brain stimulation studies have provided evidence for the role of cortical network that includes the temporoparietal junction (TPJ), the insular, and the frontoparietal cortex in SenP [66,67]. ...
Introduction:
The experience of "sensed presence" or "felt presence" in the absence of "other" has been described as a complex multimodal experience to which meaning is given. Sensed presence (SenP) is a transdiagnostic experience that exists along a continuum that can appear during isolation, spirit quests, exposure to extreme elements, bereavement, anxiety, and psychosis. Given the prevalence and vast heterogeneity of SenP, in addition to a surprising lack of targeted research into this phenomenon, this research examined the interrelationship of SenP, attenuated psychosis symptoms (APS), and transliminality. Transliminality is composed of absorption, fantasy proneness, paranormal belief, mystical experiences, increased creativity, and hyperaesthesia.
Methods:
A completely anonymous online survey of unusual experiences and mental health was distributed via social media (i.e., Twitter, Facebook, Reddit, and mass emailing lists) to recruit participants. Demographic data were analyzed using χ2 tests and one-way ANOVAs. A two-step cluster analysis was conducted to identify distinct sub-categories of transliminality followed by ANOVAs with bootstrapping at 1,000 iterations to compare SenP, increased APS, and transliminality. Pearson's bivariate correlations were conducted to determine the association between SenP, APS, and transliminality.
Results:
Together with descriptive findings, we show distinct characteristics between clusters. T1 cluster consisted of individuals with few SenP experiences, low APS, and low transliminality. T2 consisted of individuals with a moderate prevalence of SenP, low APS, moderate transliminality, and increased overall feeling of closeness to G-d. There was no significant difference in APS between T1 and T2 or in the level of distress associated with APS. T3 individuals showed a significantly higher prevalence of SenP in all domains (frequency, distress, vividness, and total score), higher APS, and higher transliminality, compared to T1 and T2. The T3 cluster met criteria for high risk to develop psychosis.
Conclusion:
Thus, our findings demonstrate a strong association and entanglement of these experiences which suggests that the interrelatedness of transliminality/absorption and APS may serve as a potentially provocative underlying structure in the phenomenology of SenP.
... Although literature suggests that felt presence experiences are common in the context of extreme sensory experiences and stress[ES4] [18,33], it is unknown if experiences of FP have increased during social isolation caused by the pandemic. With isolation inherent to social anxiety, the pandemic[ES5] presents a context where distress could manifest as social anxiety [34] and delusional beliefs. ...
Purpose: Delusional ideation, defined as false beliefs and altered thinking, has long been attributed to anomalous/bizarre perceptual experiences and reasoning deficits. Recent studies, however, have challenged this view, suggesting instead that delusional ideation may have more of a social component to its phenomenology and underlying mechanisms. This study investigated associations between delusional ideation and factors of social imagery (felt presence, empathy, loneliness, and social anxiety) in healthy adults, using the COVID-19 pandemic as a natural social experiment rich in perceived threat and social isolation.
Methods: 2,200 participants completed the online “How are you coping? COVID-19 survey,” designed to measure the psychological, social, and financial impacts of the pandemic. Delusional ideation was assessed using the Peters Delusional Ideation (PDI) scale and felt presence experiences were assessed by the Other Experiences Questionnaire (OEQ). Other measures of social imagery included the Liebowitz Social Anxiety Scale (LSAS), the Interpersonal Reactivity Index (IRI) (empathy), and the UCLA Loneliness Scale.
Results: All aspects of social imagery were positively associated with delusional ideation. The strongest predictor of PDI score was felt presence (ß=.298, p<.001), followed by loneliness (ß=.222, p<.001), LSAS (social fear dimension) (ß=.135, p=.001), IRI (empathic concern scale) (ß=.101, p<.001), and IRI (empathizing with fictitious characters scale) (ß=.088, p<.001).
Conclusion: Results support the hypothesis that delusional ideation is sensitive to alterations in sociality, and delusions may involve social cognition for representing social agents. We propose that delusions and social imagery may share common mechanisms and increased propensity for imagining others may contribute to development of delusions.
... However, apart from the entity of isolated HA psychosis, symptoms of psychosis on the mountain can also occur as part of the syndrome of organic brain dysfunction (''delirium''). Delirium at HA can occur in the context of HACE or as a result of systemic conditions such as infection or dehydration (Ryn, 1988;Brugger et al., 1999;Garrido et al., 2000;Basnyat, 2002). Hypoxia per se has a pro-hallucinogenic effect (Lempert et al., 1994). ...
Hüfner, Katharina, Fabio Caramazza, Agnieszka E. Stawinoga, Evelyn R. Pircher Nöckler, Paolo Fusar-Poli, Sanjeeb S. Bhandari, Buddha Basnyat, Monika Brodmann Maeder, Giacomo Strapazzon, Iztok Tomazin, Barbara Sperner-Unterweger, and Hermann Brugger. Assessment of psychotic symptoms in individuals exposed to very high or extreme altitude: A field study. High Alt Med Biol. xx:xxx-xxx, 2021. Background: Symptoms of psychosis such as hallucinations can occur at high or extreme altitude and have been linked to accidents on the mountain. No data are available on how to assess such symptoms in the field and what their prevalence or predisposing factors might be. Methods: In this field study at Everest Base Camp (5,365 m) in Nepal, 99 participants of organized expeditions underwent 279 assessments: The High Altitude Psychosis Questionnaire (HAPSY-Q), the Prodromal Questionnaire, 16-items (PQ-16), and the Mini International Neuropsychiatric Interview (M.I.N.I., psychosis section) were collected together with further clinical data. Statistical analysis was done for each phase, that is, altitude range of the climb, and overall data. Results: One of 97 climbers fulfilled the M.I.N.I. diagnostic criteria for psychosis during one acclimatization climb. At least one endorsed item on the HAPSY-Q and the PQ-16, indicating the presence of symptoms of psychosis in the absence of a psychotic disorders, were identified in 10/97 (10.3%) and 18/87 (20.7%) participants respectively. The scores of the HAPSY-Q and the PQ-16 were correlated (r = 0.268, p < 0.001). Odds ratio analysis identified an increased risk for accidents in individuals with endorsed items on the HAPSY-Q. Conclusions: The diagnosis of high altitude psychosis is rare in climbers during organized expeditions. Nevertheless, subdiagnostic symptoms of psychosis occurred in a significant proportion of climbers. Future research is needed to validate these pilot findings.
... Dopamine excess is also associated with near-death experiences, which involve out-of-body experiences such as moving to other worlds (Kellehear 1993;Roberts and Owen 1988). Increased dopamine levels as a result of hypoxia have also been shown in hallucinations among pilots exposed to high G forces and in high-altitude mountain climbers (Brugger et al. 1999;Buyukuysal and Mete 1999;Forster and Whinnery 1988). ...
In this paper, we present a novel hypothesis as to what led humans in the Upper Paleolithic to penetrate and decorate deep, dark caves. Many of the depictions in these caves are located in halls or narrow passages deep in the interior, navigable only with artificial light. We simulated the effect of torches on oxygen concentrations in structures similar to Paleolithic decorated caves and showed that the oxygen quickly decreased to levels known to induce a state of hypoxia. Hypoxia increases the release of dopamine in the brain, resulting in hallucinations and out-of-body experiences. We discuss the significance of caves in indigenous world views and contend that entering these deep, dark environments was a conscious choice, motivated by an understanding of the transformative nature of an underground, oxygen-depleted space. The cave environment was conceived as both a liminal space and an ontological arena, allowing early humans to maintain their connectedness with the cosmos. It was not the decoration that rendered the caves significant; rather, the significance of the chosen caves was the reason for their decoration.
... Almost everyone is susceptible to psychosis under a given set of conditions. For instance, military personnel commonly report hallucinations during strenuous training (Pallesen et al., 2018), as do individuals placed in solitary confinement (Ryan & DeVylder, 2020), individuals in sensory-deprivation chambers (Mason & Brady, 2009), and mountain climbers at high altitudes (Brugger et al., 1999). As such, we organized an emerging body of literature within a framework to delineate the relations between health and psychotic experiences. ...
... Above all, hypoxia induces psychophysiological changes in mood states, in cognitive functions and in the sensory perpcetions 5,6,11 . Abnormal visual, auditory and somatosensory-perceptions, that can be defined hallucinatory experiences, are very common at extreme altitude (above 5000 m a.s.l) 12 . These alterations are the result of a lack of serotonin caused by hypoxia, as poited out by Young 13 , who investigated the relationship between low levels of serotonin and low mood and high impulsivity in people living at a high altitude, that may induce climbers' death for suicide. ...
Altitude is a hypoxic environment known to induce several psychophysiological changes.
Previous studies found an increase of the negative emotions and a decrease of positive emotions at high altitude. In addition, hypoxia modifies the normal physiological parameters observed at sea level. In the present study we firstly hypothesized, that high altitude may affect
the somatization status and mental fatigue; secondly, that altitude is not a sufficient condition
to generate psychiatric disturbances. Moreover, the third hypothesized is an increase of the
negative emotions and a decrease of the positive emotions.
Seven volunteers climbed a mountain and underwent psychophysiological assessment
during three distinct times: before ascendance (at sea level), at Ararat Base Camp (hypoxic
natural environment 4150 m a. s. l.) and after ascendance (at sea level). Volunteers underwent psychological tests assessing somatic symptoms, perceived excertion and positive/
negative emotions. At Base Camp, a significant increase of somatic symptomatology was
observed in respect to sea-level scores. We found a significant increase in mental fatigue
at Base Camp in respect to sea-level scores. An increase of positive emotional states and a
reduction of negative states at Base Camp in respect to seal level values was found. The physiological measurements showed a significant decrease in saturation of peripheral oxygen and
a significant increase for heart rate scores at Base Camp in respect to sea-level scores, as well
as significant correlation with psychological tests.
This preliminary research shows that high altitude impairs the psychophysiological functions
and it could be considered an important parameter to predict the climbers adaptation to
hypoxia.
The World Anti-Doping Code (2021) includes a substance on the prohibited list if it meets at least two of the following: (1) it has the potential to enhance or enhances sport performance; (2) it represents an actual or potential health risk to the athlete; (3) it violates the spirit of sport. This paper uses a case study to illustrate points of tension between this code and enhancements that are appropriate to ban; we argue that there are banned drugs (e.g., acetazolamide and dexamethasone) the use of which we have good reason to not only permit but encourage for high-altitude sports. Drawing on lessons from this case study, we propose a reformulation of the Code that requires (1–3) be met but offers preferable ways of unpacking conditions (1) and (3) – and in a way that better preserves how the spirit of sport condition should be indexed to particular sports. Our formulation is inclusive enough to rule in drugs like acetazolamide and dexamethasone as permissible in high-altitude sports while at the same time ruling out problem cases – including many drugs already on the prohibited list. The result is an attempted alignment between the conditions specified and those drugs that should be banned.
Ultra-marathons are typically held over harsh terrains such as mountains, deserts, or other wilderness, and place severe demands on the physical and psychological capabilities of participants. Adventure-race competitors commonly report hallucinations. The goal of this study was to gain insight into visual hallucinations (VHs) during a mountain ultra-marathon. Thirty-one Taiwanese runners who participated in the 2018 Run Across Taiwan Ultra-Marathon, which spans 246 km with an altitude difference of 3266 m and an overall cut-off time of 44 h, volunteered for this study. Self-reported questionnaires on sleep duration, hallucinatory experiences, clinical symptoms of cold- and heat-related illnesses, and the 2018 Lake Louise Acute Mountain Sickness (AMS) Score were recorded prerace, during the summit, immediately postrace, and 3-days postrace. Hematological samples were collected 1 week before, immediately after, and 3 days after the race. Eight ultra-marathoners (six males and two females; seven finishers and one withdrawer) were recruited. Three out of eight (37.5%) subjects (two males and one female) reported experiencing VHs during the last 60 km. Three out of five (60%) lower-ranked subjects experienced VHs. All eight runners slept for <30 min during the race. None of the runners presented with headache either during or after the race to meet the criteria for AMS. None of the runners suffered an abnormal thermoregulatory response or a hypoglycemic episode throughout the ultra-marathon. The changes in blood osmolality immediately postrace were subclinical, despite being statistically significant. Among the three runners with VHs, none presented with severe dehydration or dysnatremia immediately postrace. High-altitude exposure, hyper/hypothermia, dehydration, dysnatermia, or hypoglycemia did not seem to contribute to hallucination onset in our subjects during the event. VHs of ultra-marathoners may be associated with excessive physical exertion and sleep deprivation.
Literature on the reactions of contemporary human beings coping with certain kinds of extreme and unusual environments indicates the occasional experience of another entity appearing to provide help or advice, even when no such entity was in fact present. Sources of such reports reviewed in this article include spirit quests, solitary sailing, polar and mountain explorations, and the traumatic experiences of shipwreck and air-crash survivors in remote and hostile environments. The experience is frequently interpreted as a sign of psychiatric symptomatology, whereas it is not only quite common in such situations but may in fact be an adaptive reaction. It can be conveniently described in terms of Jaynes's (1976) theory of bicamerality, but its specific etiology and characteristics have not been adequately investigated.
The endogenous opioid peptide, beta-endorphin, induces nonconvulsive limbic epileptiform activity when administered intraventricularly to rats. Epileptiform activity is elicited by beta-endorphin in doses that are devoid of analgesic or behavioral signs. Equimolar intraventricular doses of morphine or of the enkephalin analog [DAIa2,Met5]enkephalin-NH2 fail to elicit this limbic epileptiform activity. These observations, together with the recent immunohistochemical localization of beta-endorphin to midline limbic structures, suggest that beta-endorphin may have an important role in the regulation of limbic excitability.
To investigate the clinical features of transient cerebral hypoxia, syncope was induced in 56 of 59 healthy volunteers through a sequence of hyperventilation, orthostasis, and Valsalva maneuver. All events were monitored on video by two cameras. Complete syncope with falling and loss of consciousness was observed in 42 subjects, lasting 12.1 +/- 4.4 seconds. Myoclonic activity occurred in 38 of these 42 episodes (90%). The predominant movement pattern consisted of multifocal arrhythmic jerks both in proximal and distal muscles. Superposition of generalized myoclonus was common. Additional movements such as head turns, oral automatisms, and righting movements occurred in 79%. Eyes remained open throughout syncope in most subjects and initial upward deviation was common. Sixty percent reported visual and auditory hallucinations. Thirteen subjects had incomplete syncope with falls but partially preserved consciousness. These episodes were shorter and usually not accompanied by myoclonus and hallucinations. Transient amnesia and unresponsiveness without falling occurred in 1 subject.