看了美剧《Lie to me》吗？那里面的Lightman集团就是通过研究人的面部表情来判断他们是否在说谎，而这个判断过程中很重要的依据就是microexpression（微表情）。

A microexpression is a brief, involuntary facial expression shown on the face of humans when one is trying to conceal¹ or repress an emotion. They usually occur in high stakes situations, where people have something to lose or gain.

微表情是人在试图隐藏或者控制某种情绪时不自觉地表现出来、且持续时间很短的一种面部表情。微表情通常会在人们经历得失、情势危急的时候出现。

Unlike regular facial expressions, few can fake a microexpression. They consist of and completely resemble the seven universal emotions: disgust, anger, fear, sadness, happiness, surprise, and contempt. Microexpressions can occur as fast as 1/25 of a second.

跟普通的面部表情不同的是，微表情很少能够装出来。微表情能够完全反映出人类共有的厌恶、愤怒、恐惧、悲伤、幸福、惊讶以及轻蔑这七种情绪特征。微表情能在1/25秒内一闪而过。