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原帖由 子竹青青 於 2007-8-31 08:52 發表
"以前《自然》發的那個研究是直接使用電刺激，使受試者把自己的本體當成了別人。＂
在美姑娘，哪一期的＜自然＞啊，如果方便，可不可以貼出來啊？
原帖由 也和話 於 2007-8-31 13:34 發表
在美指的可能是這個, ...
Nature 419, 269 - 270 (19 Sep 2002) Brief Communications
謝謝135和也和話幫忙。135提供的是我當時寫帖時說的《科學》的兩篇論文，還不是我提到的"以前《自然》發的那個研究是直接使用電刺激，使受試者把自己的本體當成了別人＂那篇，也和話提供的是非常有趣的論文，雖然也不是我帖子里說的文章，但卻是同一研究組的先期結果。我去年就我提到的《自然》的那篇文章寫過一段讀書筆記，現轉在這裡供參考。
在美讀書筆記之二：誘發幻象影子人的啟示
人工誘發幻像影子人
（在美一方據《自然》雜誌原文摘述， 並說明如下：
1． 由於摘述者對原文中一些醫學名詞的中文說法不甚熟悉 ，若有疑問，請以原文為準，或請教醫學中文比較好的專家；
2． 此摘述並非逐字句的翻譯，部分小標題為摘述者所加；
3． 原文附后。「實驗方法和結果簡述」之4和5取自原文的補充材料。由於補充材料是PDF格式，在此並未一起給出。
4． 有需原文、插圖、和補充材料並且不能自行從《自然》下載的壇友，請向本人索取。）
摘要：對人腦左半球一個部位的刺激激發了一種有人在身邊的奇怪感覺。
關於身邊無人卻感到有人在身邊的這種奇怪感覺的現象在精神病人、神經科病人和健康人中都有報道，但是目前人們尚不了解這種幻覺是如何由大腦激發的。作者在本文中報道了對一例病人用電刺激大腦左側顳頂結反覆誘發這種幻覺的實驗。實驗中所誘發的幻象人緊隨病人自身體位和姿態的變化而改變。這些（對虛無幻象的）感知可能是來源於對大腦顳頂結部位信息處理過程的干擾，大腦顳頂結部位的這種信息處理是多感受器對身體和自我的感知。
實驗方法和結果簡述：
在一位22歲的女病人大腦上述部位植入了多個硬膜下電極。
1． 病人取卧位，電刺激電流強度10.0~11.1mA。44次電刺激均可重複誘發幻象人感覺。病人感到有人在她身後，她描述到此人年輕且性別不明。而且此「影子人」不說話也不動，正好位於她背部下方，並採取和她一樣的體位；
2． 病人取坐位，雙臂環抱膝蓋，11.0mA，1次電刺激。病人感到「那人」現在也坐著，還用雙臂箍著她，讓她感覺不舒服；
3． 病人取坐位，右手拿卡片做命名任務（語言測試），11.0mA，2次電刺激。病人感到「那人」現在坐在她右後方，並試圖干擾她完成（語言測試）任務。她描述到：「他要拿走那卡片」、「他不讓我讀（卡片）」；
4． 病人取右側卧位，11.0mA，1次電刺激。病人感到「那人」現在也是右側卧位，「用和我一樣的體位，（躺）在和我一樣的地方」；
5． 病人取左側卧位，11.0mA，1次電刺激。病人說到「有人觸摸我右側大腿」。當被問到她是否知道是誰在觸摸她時，她說「也許是那同一個人，但這更模糊」。此體位的實驗在第二天又重複了若干次。
作者評論：
由於幻象影子人可以被刺激大腦顳頂結部位而反覆誘發，又由於誘發的幻象人緊密地跟隨病人的體位和姿勢，作者認為這例病人是在感知她自己的身體。電刺激分裂了大腦顳頂結部位的多感受器和/或感知運動的功能（或處理過程），由此在體外近處誘發出了一個對自己身體的幻象。作者發現，儘管他們的病人注意到了幻象人和她本人在體位和姿態上的相似性，她並未發現那其實是對她自己身體的幻象。
在美體會：
對大腦特定部位的電刺激可以重複性地誘發人體對自身的幻象，在本文報道的實驗中，被刺激者並未察覺她感知到的其實是她自己。那麼可以推知，對大腦這個或其它部位的電或其它形式的刺激，比如壓力（腦壓異常）、化學（血氣或血葯變化）等等，有很大的可能會誘發出諸如瀕死體驗(NDE- Near death experience)和出體體驗(OBE-out of body experience) 之類的幻象。
本文首發於文學/城
《自然》原文：
Brief Communications
Nature 443, 287(21 September 2006) | doi:10.1038/443287a; Received 19 July 2006; Accepted 25 August 2006; Published online 20 September 2006
Induction of an illusory shadow person
Shahar Arzy1,3, Margitta Seeck2,3, Stephanie Ortigue3,4, Laurent Spinelli2 and Olaf Blanke1,3
Abstract
Stimulation of a site on the brain's left hemisphere prompts the creepy feeling that somebody is close by.
The strange sensation that somebody is nearby when no one is actually present has been described by psychiatric and neurological patients, as well as by healthy subjects, but it is not understood how the illusion is triggered by the brain1, 2. Here we describe the repeated induction of this sensation in a patient who was undergoing presurgical evaluation for epilepsy treatment, as a result of focal electrical stimulation of the left temporoparietal junction: the illusory person closely 'shadowed' changes in the patient's body position and posture. These perceptions may have been due to a disturbance in the multisensory processing of body and self at the temporoparietal junction.
The patient was a 22-year-old woman of normal psychiatric history who was undergoing evaluation for surgical treatment of epilepsy (see supplementary information). We identified an area on the left temporoparietal junction in her brain (Fig. 1a) where focal electrical stimulation repeatedly produced a feeling of the presence of another person in her extrapersonal space.
Figure 1: Me and my shadow.
a, Three-dimensional surface reconstruction of the left hemisphere of the brain from magnetic resonance imaging. Subdural electrodes were implanted in the brain of an epileptic patient undergoing presurgical evaluation10. The locations at which focal electrical stimulation evoked different responses are shown (red, motor; blue, somatosensory; green, language; pink, site where 'feeling of a presence' could be induced (arrow)); stars indicate the epileptic focus. Since undergoing a left-temporal lobectomy, the patient has been free of seizures. b–d, Drawings showing relative positions and postures of the patient's body (white) and that of the illusory person (shaded) during cortical stimulation (illustrations, M. Boyer).
When stimulated at this region (for methods, see supplementary information; current amplitude, 10.0 mA) in a supine position, the patient had the impression that somebody was behind her. Further stimulation (10.0–11.0 mA; n = 43) induced the same experience, with the patient describing the "person" as young and of indeterminate sex, a "shadow" who did not speak or move, and whose position beneath her back was identical to her own ("He is behind me, almost at my body, but I do not feel it"; Fig. 1b).
During the next stimulation (11.0 mA; n = 1), the patient sat and embraced her knees with her arms (Fig. 1c). She noted that the "man" was now also sitting and that he was clasping her in his arms, which she described as an unpleasant feeling. Further stimulations (11.0 mA; n = 2) were applied while the seated patient performed a naming (language-testing) task using a card held in her right hand (Fig. 1d): she again reported the presence of the sitting "person", this time displaced behind her to her right and attempting to interfere with the execution of her task ("He wants to take the card"; "He doesn't want me to read"). Similar effects were observed for different positions and postures (see supplementary information) when stimuli exceeding 10 mA were applied to the same site on the left temporoparietal junction.
The sensation of a presence, as reported by this patient, has been described in people with psychiatric and neurological disorders1, 2, 3, 4. Because it was possible to induce this feeling repeatedly from the temporoparietal junction, and because the illusory person closely mimicked the patient's body posture and position, we conclude that the patient was experiencing a perception of her own body1, 4.
The temporoparietal junction is known to be involved in self-processing, self–other distinction, the integration of multisensory body-related information, and other illusory own-body perceptions5, 6. We therefore propose that electrical stimulation of this area in our patient disturbed multisensory (proprioceptive and tactile) and sensorimotor integration of information with respect to her body, leading to the appearance of a first-rank schneiderian symptom of schizophrenia in a person with no psychiatric history. It is notable that hyperactivity in the temporoparietal cortex of patients with schizophrenia may lead to the misattribution of their own actions to other people7.
In conclusion, we argue that multisensory and/or sensorimotor disintegration8 at the temporoparietal junction due to electrical stimulation may lead to an own-body illusion of another person in near extrapersonal space. Although our patient was aware of the similarity between her own postural and positional features and those of the illusory person, she did not recognize that that person was an illusion of her own body, like many deluded schizophrenic patients3, 8, 9. Our findings may be a step towards understanding the mechanisms behind psychiatric manifestations such as paranoia, persecution and alien control. They also highlight the importance of multimodal mechanisms at the temporoparietal junction in human self-attribution.
Supplementary information accompanies this paper.
References
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2. Critchley, M. Acta Psychiatr. Neurol. Scand. 30, 155–168 (1955). | PubMed | ChemPort |
3. Jaspers, K. General Psychopathology (Manchester Univ. Press, Manchester, 1972).
4. Blanke, O. , Ortigue, S. , Coeytaux, A. , Martory, M. D. & Landis, T. Neurocase 9, 329–339 (2003). | Article | PubMed |
5. Blanke, O. , Landis, T. , Spinelli, L. & Seeck, M. Brain 127, 243–258 (2004). | Article | PubMed |
6. Ruby, P. & Decety, J. Nature Neurosci. 4, 546–550 (2001).http://www.nature.com.ezproxy.ga ... abs/nn0501_546.html
7. Farrer, C. et al. Psychiatr. Res. 131, 31–44 (2004).
8. Blakemore, S.-J. , Wolpert, D. M. & Frith, C. D. Trends Cogn. Sci. 6, 237–242 (2002). | Article | PubMed | ISI |
9. Thompson, C. Br. J. Psychiatr. 141, 628–630 (1982). | ChemPort |
10. Blanke, O. , Perrig, S. , Thut, G. , Landis, T. & Seeck, M. J. Neurol. Neurosurg. Psychiatr. 69, 553–556 (2000). | Article | PubMed | ISI | ChemPort |
1. Laboratory of Cognitive Neuroscience, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
2. Presurgical Epilepsy Evaluation Unit, University Hospital, Geneva 1211, Switzerland
3. Department of Neurology, University Hospital, Geneva 1211, Switzerland
4. Center for Cognitive Neuroscience, Dartmouth College, Dartmouth, New Hampshire 03755, USA
Correspondence to: Olaf Blanke1,3 Email: olaf.blanke@epfl.ch |
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