You wake up one morning to find a strange man standing in your kitchen. Worse than that he seems to have made himself completely at home.
当你早上醒来时，你发现自己的厨房里有个陌生人，更糟糕的是他还完全不拿自己当外人。
A child is sitting in the living room watching television, on which somebody or other is giving a speech while standing next to a bust of some old guy. Who are these people? And where's your family?
而此时客厅里有个小孩正在看电视，电视上不知是哪个人站在一个老人的半身雕像旁正在做演讲。这些人是谁？你的家人去哪里了？
If you suffered from the neurological disorder called "facial agnosia," a twilight-zone style experience of this sort might be a reality.
如果你曾经历过一种名叫面孔失认症的神经紊乱，那么这种模糊状态历可能会是真实的经历。

Facial agnosia typically occurs to people who have received damage to the right hemisphere of the brain due to stroke or injury.
一般这种面孔失认症会发生在大脑右半球曾受过重创或损伤的人身上。
People with facial agnosia lose the ability to recognize even the most familiar faces: in this case a husband and daughter, the president of the United States and a bust of Abraham Lincoln.
面孔失认症患者甚至没有能力去鉴别他们最熟悉的面孔，比如说他们的丈夫和女儿，或者美国总统和林肯半身像等等。
In severe cases an examining physician will be able to hold up a photograph of him or herself next to their own face and the patient suffering from facial agnosia will not be able to recognize the photograph is of the physician.
一些比较严重的情况是，当检查医生手拿一张医生自己的照片放在自己的脸旁时，面孔失认症患者也不能辨别出照片上的人就是医生。
What's especially interesting to researchers about this condition is its specificity. Visual ability itself is not damaged and the person with facial agnosia can still recognize everything, but faces.
使研究者觉得极为有趣的是这种病症的独特性，在视觉功能良好的情况下面孔失认症患者除了脸其他什么都仍能识别。
They can still describe faces very accurately, but only in the way one describes an object: "He needs a shave. He has droopy eyes. He has a small scar."
他们还能十分准确的描述面部特征，但是也仅限于描述具体对象：他胡子太多了，他眼袋太大，他脸上有个小疤等等。
There is never a moment of Wait a minute—this is my high school yearbook picture.
但是患者从不会有这样一刻：等等，这不是我高中时的年刊照片吗。
Facial agnosia strongly suggests the existence of a mechanism in the brain devoted specifically to recognizing individuals we've seen before, a mechanism thought to exist in many other animals and even some insects.
面孔失认症强有力的证明了大脑中有这样的特殊机制存在，它会专门致力于去辨别我们以前所见过的人，而其他动物甚至昆虫也可能拥有这种特殊机制。