英语美文背诵 为什么会怕痒（在线收听）

Have you ever thought about why people are ticklish? According to scientists, ticklishness is a defense mechanism humans developed against bugs, spiders, and other critters that may be touching our skin. Feeling ticklish is our built-in response to predators or threats, and combines the sensations of touch and pain.

你有没有想过人为什么会怕痒？根据科学家的观点，怕痒是一种防御机制，是人类把它培养来对付那些可能接触我们皮肤的虫子、蜘蛛或其它生物。怕痒是我们对侵扰者或威胁产生的内在反应，它使触觉和痛觉结合起来了。

The part of the brain that is associated with tickling is the cerebellum. It monitors our movements, but ignores movements not perceived as a threat. For example, we do not notice our vocal chords moving when we speak, but we may jump if someone touches us on the shoulder. This selective perception is probably the reason why we cannot tickle ourselves.

脑部与怕痒有关的部位是小脑。小脑监控我们的一举一动，但对其认为不具威胁性的活动，往往会忽视。举例来说，我们说话时不会察觉声带的振动，但是如有人触摸我们的肩膀时，我们可能会吓一跳。这种选择性的知觉或许就是我们无法自己哈痒的原因。