Kai@Chicago

This morning Tze told me that he had a wield sleeping experience last night.  It felt like he was pressed by something that he could not move for a while.  I was scared at first since it sounds very much like "ghost pressing on body" I heard before in Taiwan.  The last thing I'd ever want to think about is anything associated with ghost walking around in my house.  After all, I spent most of the time by myself living in this place.  Googling online, I found that it seems what he had last night was a sleeping paralysis condition which is quite common.  Most people will experience sleep paralysis at least once or twice in their lives.   In Chinese culture, sleep paralysis is widely known as 鬼壓床, and in Japanese it was called kanashibari.   Hopefully I will never have that experience.  Yuki will be here protecting me...

Here is what I found about sleep paralysis:
Source: http://tw.knowledge.yahoo.com/question/question?qid=1004120100483

正確的醫學名稱是睡眠癱瘓症(sleep paralysis)，它就是一般說謂的‘鬼壓床’。

睡眠癱瘓症通常發生在剛 入睡或是將醒未醒時，患者覺得自己已醒過來，可以聽見周遭的聲音及看到周遭的影像，但是身體卻動彈不得，也發不出聲音來，有時還會合併有幻覺。多數人在這 個時候會覺得恐慌，所幸這種情形多半在幾分鐘內會自己慢慢地或突然地恢復肢體的動作。因為在發作當時的恐慌感覺，很多人在醒來之後會覺得害怕，而直覺得認 為是被什麼不明物體壓制所造成，所以才會有‘鬼壓床’的說法。

其實，睡眠癱瘓症是發生在睡眠週期中的快速動眼期(REM stage)，快速動眼期正是我們進入熟睡開始作夢的睡眠周期。在快速動眼期中我們的骨骼肌除了呼吸肌及眼肌外，都處於極低張力的狀態。這是一種保護作 用，可以避免我們隨著夢境作出動作，而傷害到自己或是枕邊人。而睡眠癱瘓症則是因在快速動眼期中不知是什麼原因，意識已清醒過來，但是肢體的肌肉仍停留在 低張力狀態，而造成不聽意識指揮的情形。

其實睡眠癱瘓症並不少見，很多人都有過這樣的經驗，尤其是青少年及二、三十歲的 年輕人。睡眠癱瘓症可以算是一種正常的生理現象，和鬼怪無關，對身體健康也不會有什麼不良影響。它通常在壓力比較大、過度疲累、作息不正常、失眠、焦慮的 情形下比較容易發生。試著不要讓自己太累，不要熬夜，維持正常的作息通常就會減少發生的機會。