Sergent J, Villemure J G
Montreal Neurological Institute, Quebec, Canada.
Brain. 1989 Aug;112 ( Pt 4):975-95. doi: 10.1093/brain/112.4.975.
The first reported case of prosopagnosia in a right hemispherectomized woman, B.M., whose intellectual and cognitive functions were otherwise normal or only slightly impaired, is presented. She was totally unable to identify, and to experience a sense of familiarity with, faces of persons she knew, but she could evoke semantic information about them and retrieve their names from visual contextual cues. She was unaware that she was lacking face-recognition skills and that faces alone could be used to access the identity of individuals. The functional nature of her deficit was investigated through sensory, perceptual, memory, and learning tasks to determine the level at which her prosopagnosic disturbance occurred. She was defective at resolving low spatial-frequency information, but this was insufficient to explain the selectivity of her impairment. She was able to carry out cognitive operations specific to faces as long as facial identity did not have to be ascertained, and she performed as well as control subjects at deriving information about the gender, age, and emotion of faces. She was impaired at matching different views of the same faces, and multidimensional scaling analysis of dissimilarity judgements between faces indicated an inability to combine the component features into a configurational facial representation that would uniquely define each face. In contrast to recently reported cases of prosopagnosia, B.M. showed no sign of covert recognition of known faces in a learning task, and there was no indication that she could, even for a few seconds, store a faithful facial representation. The occurrence of prosopagnosia in this hemispherectomized patient confirms that this deficit can emerge without damage to the left hemisphere, and her unawareness of her deficit, which had remained unnoticed for several years, raises the possibility that other hemispherectomized patients may be prosopagnosic. The pattern of cognitive impairments displayed by B.M. indicates a perceptual basis to her disturbance and is discussed in relation to other cases of prosopagnosia.
本文报告了首例右侧大脑半球切除术后患面容失认症的女性B.M.的病例。她的智力和认知功能在其他方面正常或仅有轻微受损。她完全无法识别熟悉之人的面孔，也无法产生熟悉感，但她能唤起关于这些人的语义信息，并从视觉背景线索中回忆起他们的名字。她并未意识到自己缺乏面部识别技能，也不了解仅通过面孔就能识别他人身份。通过感觉、知觉、记忆和学习任务对她缺陷的功能性质进行了研究，以确定其面容失认障碍发生的层面。她在解析低空间频率信息方面存在缺陷，但这不足以解释其损伤的选择性。只要不必确定面部身份，她就能执行特定于面孔的认知操作，并且在从面孔中获取有关性别、年龄和情绪的信息方面，她的表现与对照组受试者相当。她在匹配同一张面孔的不同视图时存在障碍，对面孔之间差异判断的多维尺度分析表明，她无法将面部特征组合成独特定义每张面孔的构型面部表征。与最近报道的面容失认症病例不同，B.M.在学习任务中没有表现出对熟悉面孔的隐性识别迹象，也没有迹象表明她能够哪怕在几秒钟内存储忠实的面部表征。这位大脑半球切除术后患者出现面容失认症，证实了这种缺陷可以在没有左半球损伤的情况下出现，而她多年来一直未察觉自己的缺陷，这增加了其他大脑半球切除术后患者可能患有面容失认症的可能性。B.M.所表现出的认知障碍模式表明其障碍具有知觉基础，并结合其他面容失认症病例进行了讨论。
