Evidence has shown that the readings of gamma waves in peri-mortem electroencephalograms (EEGs) and their interpretation in various studies, when considered as candidates for the natural explanation of Near-Death Experiences (濒死体验), are, by all accounts, a poor bet. To support these results, you can find the review on this topic in the annex.
奥克兰大学的奈杰尔·肖, 新西兰, has developed a series of arguments explaining the inadequacies of this proposal.
Firstly, 肖解释了如何将肌肉运动误认为是脑波, giving a false impression of brain activity. 然而, this seems unlikely since EEG recordings have been obtained in some cases from patients with no type of movement.
Secondly, he references the poor determination of the moment of death in some of the studies that have found gamma activity in peri-mortem EEGs. 在一些研究中, the EEGs are clearly before cardiac arrest, others when no pulse is detected, and others during effective cardiorespiratory arrest.
Shaw’s strongest argument comes from studies with dogs, which found that EEGs with gamma activity originate from the brain’s amygdala and not the cortex, making it unlikely that such activity could be proposed as the cause of NDEs.
Moreover, Shaw argues that the relationship between gamma waves and consciousness has never been fully established: 例如, someone can generate gamma waves in the EEG and yet be under anesthesia.
最后, the author highlights that in psychedelic states, where some characteristics of NDEs are reproduced, EEG记录的整个脑波频谱, 包括伽马波, is reduced; adding difficulty to the possibility that these types of peri-mortem waves could be responsible for NDEs.
奥斯卡·洛伦斯和加西亚
ANNEX
审查 Characterization of End-of-Life Electroencephalographic Surges in Critically Ill Patients by Chawla et al., 2017.
In 2009, Lakhmir Chawla的团队检测到 End-of-Life Electrical Surges (他们) 在 7 患者之间 3-5 心肺骤停后几分钟. 八年后, 他们设法复制了这些结果的一部分: 13 出于 18 patients experienced ELES. 在 2009 文章, these ELES were proposed as a possible neurophysiological cause for Near-Death Experiences (濒死体验).
Chawla强调了Auyong的研究 (2010), 前进 (2013), 和范莱恩 (2011) 证实他的结果. 然而, 在第一个研究中, 心脏骤停的确切时刻不包括; 在第二个, electroencephalogram activity occurs in mice within 30 心肺骤停后几秒, as expected following such arrest, 和博士. Borjigin herself complained that the results obtained by Chawla were different from those recorded by her team; and in the third, it is ruled out that such experiences, found by the authors in decapitated rodents, can be associated with any type of consciousness, 鉴于该现象发生在麻醉和非麻醉小鼠中.
The results from Norton (2017), 睡眠 (2021), 里根 (2018), 德弗里斯 (1998), 总共有 197 案例, 和Pana的荟萃分析 (2016) 和 7 human studies and 10 animal studies, did not validate Chawla’s results and found either a generalized decrease or no brain activity after cardiorespiratory arrest.
When adding to these results the fact that some NDEs occur before 3 minutes into the arrest thanks to their in-hospital origin and an adequate resuscitation protocol, it becomes difficult to attribute NDEs to ELES.
实际上, ELES seem to be the result of neuron depolarization in a severely damaged brain.
