作者：Susan Jeffrey
出處：WebMD醫學新聞
November 6, 2007 — 研究者報導他們能夠重複地且可靠地對一位為了抑制耳鳴植入電極的病患，造成一種靈魂出竅的體驗。第一作者比利時安特衛普大學醫院神經外科部Dirk De Ridder醫師表示，我們可以刻意地重複製造出這種體驗，且是以一種完全安慰劑控制的方式進行，因為該名病患無法得知什麼時候刺激器是開著的。
這項研究報告發表在11月1日的新英格蘭醫學期刊。
作者指出，靈魂出竅的體驗是一種短暫的主觀感覺，此時你會感到你的自己離開你的軀體，可能會有或是沒有從升起或較遠距離看到自己軀體的印象。
這裡所報導的是一位63歲來自丹麥的男性，他已經被轉介到當地的機構，且接受植入電極，位置在右側的顳頂葉交界處，目的是在壓抑難以治療的耳鳴。
De Ridder醫師表示，他們使用一種新型且更具威力的刺激方法，發現病患接受這個刺激後會產生靈魂出竅的體驗。
在該名病患的同意之下，他們能夠準確地再現這種感覺，但只有在這些參數下才有這樣的反應；他表示，當我們些微降低電壓，即使只有1伏特，就不會發生這種現象。
因為這個經驗大約持續17秒鐘，他們能夠在安慰劑控制的情況下進行正子攝影（PET）掃描，且定位到顳頂葉交界處的活化、或是更仔細地說，是角回與緣上回之間交界處，以及上顳回與右側上顳溝；在右側契前葉與後視丘在刺激之下也可以看到活化，會延展到小腦上蚓部。
他們指出，我們證實這些區域的活化與脫離形體神經上的關連，且這是靈魂出竅經驗的一部份。
De Ridder醫師表示，這些發現並不如瀕死經驗那樣的有關聯，自發性的靈魂出竅體驗過去也曾於癲癇病患、偏頭痛病患身上發現，且在最近的一項報告中，也曾在一位使用虛擬實境系統的健康自願者身上看到，雖然並不是以像這樣可靠的方法證實。
他指出，這是神經網路牽涉到靈魂出竅體驗的一個簡單的描述。
他表示，仍有許多植入電極於同樣位置的病患，可能可以邀請他們加入往後的研究；De Ridder醫師表示，機構的倫理委員會核准第一位病患的原因在於要檢驗植入電極的副作用、以及聽覺皮質刺激的併發症，因此這項研究是技術上由該核准案涵蓋的；若要在其他病患身上研究此種效應，則需要新的核准案。
作者表示對該文章沒有相關資金上的衝突。
Brain Stimulation Produces "Out-of-Body" Experience
By Susan Jeffrey
Medscape Medical News
November 6, 2007 — Researchers are reporting they were able to repeatedly and reliably elicit an "out-of-body" experience in a patient in whom electrodes had been implanted to suppress tinnitus.
"We were able to reproduce the effect at will and in a completely placebo-controlled way, because the patient was not able to tell when the stimulator was on," first author Dirk De Ridder MD, PhD, from the department of neurosurgery at the University Hospital Antwerp, in Belgium, told Medscape Neurology & Neurosurgery.
Their report appears in the November 1 issue of the New England Journal of Medicine.
An out-of-body experience is a brief subjective episode in which the self is perceived as being outside of the body, with or without the impression of seeing the body from an elevated and distanced perspective, the authors write.
The case reported here was of a 63-year-old man from Denmark who had been referred to their institution and received implanted electrodes overlying the temporoparietal junction on the right side in an attempt to suppress intractable tinnitus.
They had been using a new and more powerful method of stimulation and found the patient had an out-of-body experience with this method. "We stopped immediately and noted the exact parameters of the stimulation," Dr. De Ridder said.
With the patient's permission, they were able to exactly reproduce the sensation, but only at these certain parameters. "When we lowered the stimulation by just 1 V, it didn't happen," he noted.
Because the experiences lasted around 17 seconds, they were able to perform positron emission tomography (PET) scanning in a placebo-controlled way and locate the activation to the temporoparietal junction, or more specifically, the angular–supramarginal gyrus junction and the superior temporal gyrus–sulcus on the right side. Activation was also seen at the right precuneus and posterior thalamus with stimulation, extending into the superior vermis.
"We suggest that activation of these regions is the neural correlate of the disembodiment that is part of the out-of-body experience," they write.
These findings have no implications for the out-of-body experience as it relates to near-death experiences, Dr. De Ridder said. Spontaneous out-of-body experiences have also been previously reported in epileptic patients, those with migraine, and, in a recent report, have been induced in healthy volunteers using a virtual-reality system, although not in this kind of reliable way.
"This is simply a description of the neural network that's involved in the out-of-body experience," he said.
They have some other patients who have electrodes implanted in the same location and may approach them about participating in a further study of this effect, he said. The institutional review board approval for the first patient was to look at side effects and complications of auditory cortex stimulation, so this study was technically covered by that approval, Dr. De Ridder noted. To study this effect in other patients will require a new application.
The authors report no conflict of interest relevant to this article.
N Engl J Med. 2007;357;1829-1833. Abstract
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