What It’s Like to Have Face Blindness
患脸盲症是怎么回事
By Daniel Gibbs
文/丹尼尔·吉布斯
译/王昊堃
Recently, while out walking my dog Jack, I encountered a blond woman pushing a toddler in a stroller while walking her dog. I stopped to chat, asking her how old her son was now, and she responded amiably. About a year and a half ago, three women on our block gave birth within a month of each other. One woman has blond hair and two have dark hair. They all have dogs. As soon as we had ended our chat and I was walking on, I realized that she had the wrong dog. The blond on our block has a black lab1, and this dog was some kind of curly-haired terrier2. I then realized that the woman I had approached was a complete stranger, not one of my neighbors.
最近，我在遛狗狗杰克时，遇见了一位同在遛狗的金发女士，她推着婴儿车，车里坐着一个看样子正在学步的小男孩。我停下来与她交谈，问她儿子多大了，她友善地回应了我。大约一年半前，我们街区有三位女士在一个月内先后生了孩子，她们当中一人是金发，两人是黑发，并且三人都养狗。就在我们刚刚结束聊天、我继续往前走时，我意识到这只狗并不是她的。我们街区那位金发女士养了一只黑色的拉布拉多，而这只是一种卷毛小猎狗。我恍然大悟，刚刚与我交谈的女士完全是个陌生人，并非我那三位邻居之一。
On the face of it, this wouldn’t be a particularly noteworthy incident, given the context of the COVID pandemic that has so many of us wearing masks. It has become a common, shared experience, these awkward social moments in which we’ve failed to recognize people we know, or we’ve been on the receiving end3 of someone we know looking right past us as if we’re strangers. But the moment held more for me.
表面看来，在许多人因新冠疫情都要佩戴口罩的情况下，这并不是一件多么值得注意的事。我们没能认出认识的人，或是认识的人没能认出我们，如同面对陌生人，这些社交场合的尴尬瞬间已经成了人人都有的经历。但这一刻对我来说却有着非同寻常的意义。
I am a retired neurologist. I also have early-stage Alzheimer’s disease. During my 25 years practicing general neurology in Portland, Ore., I took care of many patients with dementia, including Alzheimer’s disease. I never suspected that I too might get Alzheimer’s, but then about 15 years ago I started to lose my sense of smell and began to experience stereotypical phantom odors called phantosmias4. Problems with smell can be early symptoms of neurodegenerative5 diseases like Alzheimer’s, but it was another six or seven years before I started to have issues with my memory. The neuropathology6 of Alzheimer’s disease, the beta-amyloid plaques7 and tau-containing neurofibrillary tangles, are found first in olfactory centers in the brain, years before cognitive impairment begins. As part of a research study, I underwent amyloid and tau PET8 scans of my brain in 2015 and again in 2018, and the scans confirmed the diagnosis and progression of Alzheimer’s disease.
我是一名退休的神经学家，患有早期阿尔茨海默病。我在俄勒冈州波特兰市从事普通神经学研究已有25年，其间治疗过许多患有包括阿尔茨海默病在内的痴呆病人。我从未想到自己会患上阿尔茨海默病。然而，大约15年前，我开始失去嗅觉，典型的症状就是会闻到实际上并不存在的臭味，这叫“嗅幻觉”。嗅觉出现问题可能是阿尔茨海默病之类的神经退行性疾病的早期症状，而我的记忆开始出现问题是六七年之后的事了。阿尔茨海默病的神经病理学表明，在人体发生认知障碍的几年前，大脑嗅觉中枢就已经存在β-淀粉样斑块和含tau蛋白的神经原纤维缠结。我在2015和2018年先后做了两次“派特”，检测脑部的淀粉样蛋白和tau蛋白含量，这也是一次研究的组成部分。扫描确诊我患上了阿尔茨海默病，并且显示病情在恶化。
Being a neurologist with a neurological disorder has provided me some special insights. For example, seeing beta-amyloid on my first amyloid PET scan located not only in the prefrontal cortex9 and precuneus10 but also in olfactory processing centers such as the piriform cortex11 and orbital frontal cortex12 was really exciting because it provided a logical explanation for my olfactory problems. The PET scans also gave me some hints as to the cause of my trouble recognizing my neighbors.
作为一名神经学家，患上神经功能障碍倒是让我有了一些独到的认识。比如，我的第一张淀粉样蛋白派特图显示，β-淀粉样蛋白不仅位于前额皮层和楔前叶，同时还存在于梨状皮层和眶额皮层等嗅觉处理中枢。我对此格外兴奋，因为这样，我的嗅觉问题就解释得通了。派特扫描还给了我一些线索，帮助我找到认不出邻居的原因。
Face blindness, or prosopagnosia13, is a neurological condition resulting in trouble identifying human faces. It is usually caused by damage to the fusiform gyrus14 in the posterior temporal lobe15 and anterior16 portion of the occipital lobe17. Neurologist-author Oliver Sacks famously introduced this condition to popular culture in his 1985 book The Man Who Mistook His Wife for a Hat. Sacks wrote about his own severe face blindness in a wonderful, August 23, 2010, article in the New Yorker. One of my neurologist colleagues has such severe face blindness that she needs to hear someone speak before reliably making an identification. Like Sacks, she’s had it all her life. Up to 2.5 percent of people are born with congenital18 face blindness, mostly inherited in an autosomal19 dominant pattern.
脸盲，也叫面容失认症，是一种神经系统疾病，具体表现为辨别人脸困难，通常由后颞叶和枕叶前部梭状回损伤导致。众所周知，神经学家兼作家奥利弗·萨克斯在其1985年的著作《错把妻子当帽子》中将这一疾病引入大众文化。2010年8月23日发行的《纽约客》曾刊登过萨克斯的一篇精彩文章，其中就写到他自己患有严重的脸盲症。我的一位神经学家同事也有严重的脸盲症，她需要听到对方说话才能确认此人的身份。和萨克斯一样，脸盲症伴随了她一生。高达2.5%的人患有先天性脸盲症，其中大多数是常染色体显性遗传所致。
Acquired face blindness may be caused by head trauma, strokes or tumors affecting the fusiform gyrus. A more insidious20 form of face blindness occurs in many people with Alzheimer’s disease, even in the early stages. The tau-containing neurofibrillary tangles of Alzheimer’s disease usually first occur in the medial21 portion of the anterior temporal lobes. With time, these neurofibrillary tangles can spread backwards into the fusiform gyrus.
导致后天脸盲症的原因可能是头部创伤、中风或肿瘤影响到了梭状回。脸盲症还会以一种更加隐蔽的方式存在于许多阿尔茨海默病患者体内，甚至病程早期就已存在。阿尔茨海默病的含tau蛋白的神经原纤维缠结通常首先出现在前颞叶中部。随着时间推移，这些神经原纤维缠结会向后蔓延至梭状回。
Although my cognitive impairment is still mild, I have been having increasing trouble recognizing faces, even of people I know well. Many of my neighbors are hard for me to recognize until I hear their voices or see the dog they are walking. Before the pandemic, I would often be embarrassed by not recognizing or misidentifying an acquaintance while walking my dog.
我的认知障碍不算太严重，但在认人方面却越来越困难，甚至包括熟人。许多邻居我已经很难辨认，除非听到他们的声音或看到他们遛的狗。疫情之前，我在遛狗时，常会因为认不出或认错人而感到尴尬。
Our masks are now covering important facial features used for facial recognition. A recent study from York University in Toronto and Ben-Gurion University in Israel confirmed this by demonstrating “quantitative and qualitative changes in the [visual] processing of masked faces” that “could have significant effects on activities of daily living.” Perhaps everyone now is experiencing a degree of face blindness.
戴上口罩，识别人脸所需的几项重要面部特征便被遮住了。加拿大约克大学和以色列本·古里安大学近期的一项研究演示了“大脑对戴上口罩的人脸进行（视觉）处理时量和质的变化可能给日常生活中的各类活动带来显著影响”，由此证实了这一点。或许我们每个人都正在体验一定程度的脸盲。
The ability to accurately identify other people by recognizing their faces is important to our social, emotional and cultural behaviors. Our brains appear to learn how to recognize the faces of other people of our race during childhood. A study in 2019 showed that there is a critical period for this learning. Children learn how to recognize faces of the group they are raised with, up until about age 12. White children will become adept at distinguishing white faces, but unless they are exposed to other racial faces, they will have trouble distinguishing people of other races.
通过辨认人脸来准确识别人，这一能力对于我们的社交、情感及文化行为都非常重要。我们的大脑似乎在幼年时就学着如何辨认同一种族其他人的脸了。2019年的一项研究表明，辨认人脸的学习有一段关键时期。一直到12岁左右，儿童都在学习如何辨认他们成长过程中身边人的脸。白人儿童会变得擅长辨认白种人的脸，而辨认其他种族人的脸就会有难度，除非与其他种族的人共处。
Similarly, an Asian child raised in an Asian country without exposure to white faces will not be able to distinguish white faces. An Asian child adopted and raised in a predominantly white country will distinguish white faces but not Asian faces. A child who grows up in a racially heterogeneous22 setting will be able to distinguish faces of all of those races. This learning process slows down and then is gone by age 12.
同样，一个在亚洲国家长大的亚洲儿童，如果不与白种人共处，就不会辨认白种人的脸。一个亚洲儿童被领养并在以白种人为主的国家长大，就会辨认白种人的脸，却不会辨认亚洲人的脸。一个在多种族混居环境中长大的孩子将会辨认所有相关种族人的脸。学习辨认人脸的过程在12岁之前会逐渐减缓，直至消失。
To me this implies that there are pathways in the brain, probably in the fusiform gyrus, that are developing new neuronal23 connections during childhood as we learn what makes one face look different from another, but that this plasticity24 is lost by age 12. It strikes me that while face masks are drawing our attention to the subject of face blindness, more relevant may be the impact of our children’s social exposure that supports how they see others, literally, in our diverse communities.
对我来说，这意味着大脑中——很可能就在梭状回中——存在着一些通路，我们在孩童时期学习辨认不同人脸的区别时，这些通路就在不断建立新的神经元连接，不过这种可塑性到12 岁就消失了。口罩引起了我们对脸盲这个话题的关注，但我认为更有意义的或许是，在这个多元化的社会里，接触的群体与环境对孩子们发展认人能力的影响。
I’ll need to attend closely to those masked faces to overcome my combined disadvantage of neurological face blindness and masked face blindness, the first caused by abnormalities of the brain and the second simply due to the blocking of visual cues. My best option may be to pay closer attention to the dogs. Even for me, pets are easy to identify because of shape, size, color of coat and sometimes temperament or behavior. I’ll also need to expand my mental dog gallery now to include that curly terrier and his friendly human companion with the baby stroller. Next time we pass on the street, we’ll be strangers no more.
我得密切注意那些戴着口罩的路人，以便克服我的两个弱点：一个是因大脑异常导致的神经学意义上的脸盲，而另一个仅仅是因面部特征被遮挡导致的脸盲。对我来说，最佳的选择或许是给予狗狗们更密切的关注。因为即便对于我这种认脸有困难的人，也可以根据体形、块头、皮毛颜色，以及脾气或行为，轻易辨认出不同的宠物。同时，我也要扩充我脑海中的狗狗图库，把那只卷毛小猎狗加进去，还有它那位友善的推着婴儿车的人类伙伴。下次在大街上相遇，我们便不再是陌生人。
（译者为“《英语世界》杯”翻译大赛获奖者）
注释：
1. lab = labrador 拉布拉多猎犬。
2. terrier 㹴犬，一种活泼的小狗。
3. be on the receiving end 遭受，承受（不愉快的事）。
4. phantosmia 嗅幻觉，指患者通常会闻到排泄物或下水道的味道。
5. neurodegenerative 神经退行性的。
6. neuropathology 神经病理学。
7. beta-amyloid plaque β-淀粉样斑块。
8. = Positron Emission Computed Tomography 正电子发射型计算机断层显像，是核医学领域比较先进的临床检查影像技术。
9. prefrontal cortex 前额皮层。
10. precuneus 楔前叶。
11. piriform cortex 梨状皮层。
12. orbital frontal cortex 眶额皮层。
13. prosopagnosia 面容失认症。
14. fusiform gyrus 梭状回，大脑颞叶及枕叶之间的皮层，最主要的作用是识别人脸。普通人看到人脸时，其神经活跃度会变高。
15. posterior temporal lobe 后颞叶。
16. anterior 前部的。
17. occipital lobe 枕叶。
18. congenital 先天性的。
19. autosomal 常染色体的。
20. insidious 潜伏的。
21. medial 中间的，平均的。
22. heterogeneous 各种各样的，混杂的。
23. neuronal 神经元的，神经细胞的。
24. plasticity 可塑性，适应性。