探究面孔失认症个体的面孔空间。
Probing the face-space of individuals with prosopagnosia.
机构信息
Department of Psychology, Carnegie Mellon University, Pittsburgh, PA 15213-3890, USA.
出版信息
Neuropsychologia. 2010 May;48(6):1828-41. doi: 10.1016/j.neuropsychologia.2010.03.007. Epub 2010 Mar 19.
A useful framework for understanding the mental representation of facial identity is face-space (Valentine, 1991), a multi-dimensional cognitive map in which individual faces are coded relative to the average of previously encountered faces, and in which the distance among faces represents their perceived similarity. We examined whether individuals with prosopagnosia, a disorder characterized by an inability to recognize familiar faces despite normal visual acuity and intellectual abilities, evince behavior consistent with this underlying representational schema. To do so, we compared the performance of 6 individuals with congenital prosopagnosia (CP), with a group of age- and gender-matched control participants in a series of experiments involving judgments of facial identity. We used digital images of male and female faces and morphed them to varying degrees relative to an average face, to create caricatures, anti-caricatures, and anti-faces (i.e. faces of the opposite identity). Across 5 behavioral tasks, CP individuals' performance was similar to that of the control group and consistent with the face-space framework. As a test of the sensitivity of our measures in revealing face processing abnormalities, we also tested a single acquired prosopagnosic (AP) individual, whose performance on the same tasks deviated significantly from the control and CP groups. The findings suggest that, despite an inability to recognize individual identities, CPs perceive faces in a manner consistent with norm-based coding of facial identity, although their representation is likely supported by a feature-based strategy. We suggest that the apparently normal posterior cortical regions, including the fusiform face area, serve as the neural substrate for at least a coarse, feature-based face-space map in CP and that their face recognition impairment arises from the disconnection between these regions and more anterior cortical sites.
理解面部身份心理表现的一个有用框架是面孔空间(Valentine,1991),这是一个多维认知图,其中个体面孔相对于之前遇到的面孔的平均值进行编码,并且面孔之间的距离代表它们的感知相似性。我们研究了是否患有面孔失认症的个体,这种疾病的特征是尽管视力和智力正常,但无法识别熟悉的面孔,他们的行为是否符合这种潜在的代表性模式。为此,我们将 6 名先天性面孔失认症(CP)患者的表现与一组年龄和性别匹配的对照组参与者在一系列涉及面孔身份判断的实验中进行了比较。我们使用男性和女性面孔的数字图像,并相对于平均面孔进行不同程度的变形,以创建漫画、反漫画和反面孔(即相反身份的面孔)。在 5 项行为任务中,CP 个体的表现与对照组相似,与面孔空间框架一致。作为对我们的测量方法揭示面孔处理异常敏感性的测试,我们还测试了一名后天性面孔失认症(AP)个体,其在相同任务上的表现与对照组和 CP 组明显不同。研究结果表明,尽管 CP 个体无法识别个体身份,但他们以与基于规范的面孔身份编码一致的方式感知面孔,尽管他们的表示可能基于基于特征的策略得到支持。我们认为,即使在 CP 中,包括梭状回面孔区在内的明显正常的后皮质区域也可能作为神经基础,至少为基于特征的粗糙面孔空间图提供支持,并且他们的面孔识别障碍是由于这些区域与更前部皮质区域之间的断开连接引起的。