Sleep paralysis，也叫梦魇，是指人的意识处于半梦半醒时身体不能动的一种状态。乡俚的说法，就是“被鬼压”。大多数人都必然曾经历过起码一次吧，我是经常遇到的。

科学家现在还不能解释，究竟是什么原因导致梦魇，只是归纳了一些它的特点，例如和某些疾病关系密切等。有趣的一项调查说梦魇发生在非裔美国人身上的机率远远高于美国白人。而他们的非裔社区则把这种梦魇现象称之为“The Witch Riding Your Back”.女巫骑在你背上。在对超自然现象的迷信方面，全世界人民难分高下。不同的是，我们怕鬼，他们怕女巫。

每一次的梦魇，都让我惊惶不已，尽管知道，它只是暂时现象，它会消失的，但恐惧还是会紧紧地拽着我，把我拖入意识迷离的万丈深渊。幻觉，总是伴随梦魇而来的，它们又如此生动，真实，常让人分不清现实或是梦境。我记忆最初的，也最深的一次梦魇，发生在我读小学，大概八、九岁的年龄。头一天晚上，趁家人都歇息了，我偷偷把房间灯开了看小说，书读着读着就睡过去了，灯忘记关掉。次日清晨，当我的意识渐渐从黑暗中走出来时，我的身体却没跟上它的步伐。我分明地看到房间弥漫着橘黄色的灯光。一切如常，除了感到自己的身体有点沉重之外，我从床上爬起来，穿上拖鞋，站起来，把灯关上，我看到了家人，和他们打招呼，然后去刷牙洗脸......这些感觉是那么真实，让我没有一点怀疑。忽然，我的意识世界，被什么晃悠了一下，如同镜花水月的被打破，它一下就乱套了。脱节了，断裂了，模糊不清了，眼前一切均消失无踪，只有那像符咒一样困住我的灯光，依然明亮，还有我那身体，仍然躺在床上。是的，我的意识好像旁观者，它能看到它的老伙伴--肉身的无助。

那种惊恐无助，自然是笔墨难以形容的。我想呼唤，也用尽全力，去呐喊，可是，只有空虚，什么都没有。我用尽全力，企图把自己拖起来，而我的身体如磐石，纹丝不动。接着，这种自我拯救因用力过度，很快又将自己拖回那种真实的幻觉世界里，反反复复的徘徊于两个世界里，到后来，人会感到精疲力尽，几乎虚脱。深深的孤独感，无力感，泛在心头。如同流落孤岛，被世界抛弃了，没有出路。

也许，那种由始至终伴随着人的孤独感，最初都是源于生命里这些可怕的体验---梦魇？梦魇过去了，但那种孤独无助荒凉迷离的感受就好像火的烙印刻在个人的潜意识里？

梦魇的结束无法预知，但它们是脆弱的，敏感的，只需要外部世界小小的、一丁点的任何变动，例如风吹过铃铛，敲门的声音，某人在旁边说话......都马上能结束这地狱一般的旅程，让人迅速回到现实。我那一次梦魇的结束，是终于等到我父亲起床了，他看见我房间明晃晃的随手就拉了一下线，把灯给关了。我的身体也在一刹那，完全苏醒过来了。浴火重生的凤凰，其华丽也不过如此。

从那以后，二十几年的岁月里，经历过无数次的梦魇。尽管，我每次都告诉自己，那只是暂时的，我会出去的，不要惊慌，但那种惶恐的感觉也始终是摆脱不了，尤其是一个人在漆黑的、锁了门的、偏僻安静的房间时。那意识世界的鲁宾逊漂流何时结束，只能全凭运气了。

也许，人类社会之所以产生婚姻制度，都出于对梦魇的恐惧。梦魇里的幻觉如此栩栩如生，想象一下我们的老祖宗，那么粗粝的生存环境下，在梦魇里都得经历什么吧，不是猛禽就是野兽，必定都是血淋淋的场面，再醒不过来，估计都要被吓死了。身边有个人躺着，总比一个人伶仃，要保险许多。

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小曼,正好看到有关解释,只好麻烦我为你抄一段了.

Although not every out-of-body experience (OBE) has identical features, there are a number of common trails.They invariably occur during sleep, on the verge of sleep or while losing consciousness. Often the sleep is not particularly deep, perhaps due to illness, emotional stress or exhaustion.The person then "wakes up"and in many cases experiences a sense of physical paralysis.  People remember trying to move limbs during OBEs, but to no avail. Only the eyes seem to function properly.  Those who were undergoing life-saving surgery at the time frequently remember looking down at their bodies from above and seeing doctors trying to perform resuscitation. The OBE usually lasts for no longer than a minute and is sometimes ended by a fear of getting too far away from the body. Suddenly there is a feeling of being pulled back into the body and the experience is over.

OBEs are often linked to escape from extreme pain and trauma.......

Not all OBEs are accompanied by sleep.Susan Blackmore, a leading authority on OBEs, experienced her own while a student at Oxford University in 1970s. She describes her state of mind at the time as "fairly peculiar"and recounts how she went down a tunnel of trees toward a light before floating on the ceiling and observing her body below.she then floated out of the building and across and Atlantic to New York.  After hovering around New York, she drifted back to her room in Oxford where she shrank in size and entered her body's toes.
......
The Swiss doctors concluded that the angular gyrus plays a key role in matching up visual information of the brain's touch and balance representation of the body.  When the become dissociated, an out-of-body experience may result. The researchers also noted that the OBE tends to disappear when the person attempts to inspect the illusory body or body part.

The evidence of the Swiss doctors supports the view that at least some OBEs are caused by an unusual brain state in which one's body perception and sense of reality are altered. How much faith can we place in OBEs though? While it is impossible to disprove their existence, as yet there has there been no firm proof that anyone has ever actually left their body during these episodes. Ed Morrell's tale of witnessing a real-life shipwreck may sound convincing, but like other similar claims, its veracity has not been tested to the satisfaction of the scientific world.  Until such evidence is forthcoming, many scientists believe that out-of-body experiences are simply vivid dreams, hallucinations or the product of hysteria, brought about by a particularly traumatic event.

小曼,在你十来岁的时候,是不是经常陷入沉思冥想而对周围浑而不觉,直到什么人打你一下,你才从中醒过来?

>>>小曼,在你十来岁的时候,是不是经常陷入沉思冥想而对周围浑而不觉,直到什么人打你一下,你才从中醒过来?

-----俺现在也经常如此

藏西，我现在也偶尔会这样，不过，确实在我十几岁的时候常有这种事情，我从小到大都喜欢胡思乱想，也比较内向。

灵魂出窍？
失去控制，所以害怕？

我比较倾向于接受这样一种说法，梦魇是关于前世的记忆残存。我想不是说前世一定这么可怕（当然应该一世更比一世好），而是碎片难以拼出一幅美好图画。

小时候生活有变迁时，噩梦最多。生活平缓时，梦也是平淡的，多是些平凡琐事，毫不稀奇。在高中时有过类似OBE的经历，只有一次，以后再没有昏厥的经历。平时人健康时不可能有OBE。这有可能只是normal brain function, 说不清楚的事。