Brugger P, Regard M, Landis T, Oelz O
Department of Neurology, University Hospital Zürich, Switzerland.
Neuropsychiatry Neuropsychol Behav Neurol. 1999 Jan;12(1):67-71.
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.
本研究试图对一组高度专业化的健康受试者——极端海拔登山者——异常感知体验的发生率、类型及情况进行系统调查。
有轶事证据表明在高海拔登山过程中异常感知体验的发生率很高。
在一次结构化访谈中，我们询问了八位世界级登山者，他们每人都在未使用辅助氧气的情况下攀登到了海拔8500米以上，询问他们在不同海拔登山过程中的幻觉体验。在访谈后的一周内进行了全面的神经心理学、脑电图和磁共振成像评估（8）。
除一名受试者外，所有受试者均报告了本体感觉错觉（身体图式的扭曲）以及视觉和听觉假性幻觉（按此发生频率顺序）。报告的海拔6000米以上的体验数量与海拔6000米以下相比不成比例地多（相对于在这些不同海拔所花费的总时间）。独自攀登以及（就本体感觉错觉而言）危及生命的危险被确定为异常感知体验的可能触发因素。未发现报告的体验数量与神经心理学损害之间存在关联。脑电图（3名登山者）和磁共振成像（2名登山者）结果中的异常同样与报告的幻觉体验频率无关。
结果证实了早期轶事证据，即在高海拔登山过程中幻觉体验的发生率相当高。除了缺氧外，社交剥夺和急性应激似乎在这些体验的发生中起作用。
