感想：8 I$ A- B) K( I/ S" _- D& U
第一遍泛听时几个关键词反应不过来，比如blind, sighted, hormone，所以听的时候比较蒙……听写时还好点……- C' g* O4 J! e" M) ]
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5月17日
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h7 k3 L; t9 ~/ H0 h# Y8 R. |(76) 人体生理心理：第6篇（sleep）---难度级别：$$$半
1 ] |; d$ q8 a% n3 V# yDid you ever wonder why it is that most peolple are (“programmed to”) sleep at night instead of during the day?! a w9 T' J$ m1 y! v: \9 A
If there`s something about (the cycle of) light and dark that`s telling us when to sleep, then shouldn`t the sleep cycle of a blind person be different? As it turns out, many blind people---people with no <visual> perception of light at all---do have the same sleep cycle (as sighted有视力的) people.
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So, now you`re wondering, “How can this happen?” The anwser is: <hormones荷尔蒙>---one hormone in particular. It called (melatonin). In sighted people, the level of malatonin goes up at the night (or when it`s dark) and goes down in the day (or when it`s light). It believed that it`s the (presence) of this hormone in the blood that gives us the urge to sleep. If (an) increase (in) malatonin level “programs” sighted people to sleep at night, then what about blind people?, f& w9 c" x7 D8 u
7 T8 j) V# a' ?A researcher named Dr. Charles Czeisler, tells about an interesting experiment. he tried to shining a bright light into the eyes of some blind people. When he did this, he notices that level of the malatonion in the blood of , E; B) x5 e4 }: a
these subjects went down---just (as it would) do for sighted people. Somehow, the eyses of these subjuects, even though they were damaged and had no visual (perception知觉，领悟力 of light), could tell (their brain when there was more or less light) . Now, this doesn`t work for all these blind people. In fact, most of (Czeisler`s) subjects has no hormonal response (to light) at all. Further research may be able to explain this sensitivity to light in terms of (the type of blindness) of the subjuct.
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[ 本帖最后由 穗棉布族 于 2008-5-18 23:22 编辑 ]
