Pourtois Gilles, Schwartz Sophie, Seghier Mohamed L, Lazeyras François, Vuilleumier Patrik
Department of Neurosciences, Neurology and Imaging of Cognition, Clinic of Neurology, University Hospital, University Medical Center, Switzerland.
Neuroimage. 2005 Feb 15;24(4):1214-24. doi: 10.1016/j.neuroimage.2004.10.038. Epub 2004 Dec 19.
Face recognition is a unique visual skill enabling us to recognize a large number of person identities, despite many differences in the visual image from one exposure to another due to changes in viewpoint, illumination, or simply passage of time. Previous familiarity with a face may facilitate recognition when visual changes are important. Using event-related fMRI in 13 healthy observers, we studied the brain systems involved in extracting face identity independent of modifications in visual appearance during a repetition priming paradigm in which two different photographs of the same face (either famous or unfamiliar) were repeated at varying delays. We found that functionally defined face-selective areas in the lateral fusiform cortex showed no repetition effects for faces across changes in image views, irrespective of pre-existing familiarity, suggesting that face representations formed in this region do not generalize across different visual images, even for well-known faces. Repetition of different but easily recognizable views of an unfamiliar face produced selective repetition decreases in a medial portion of the right fusiform gyrus, whereas distinct views of a famous face produced repetition decreases in left middle temporal and left inferior frontal cortex selectively, but no decreases in fusiform cortex. These findings reveal that different views of the same familiar face may not be integrated within a single representation at initial perceptual stages subserved by the fusiform face areas, but rather involve later processing stages where more abstract identity information is accessed.
人脸识别是一项独特的视觉技能，使我们能够识别大量的个人身份，尽管由于视角、光照变化或仅仅是时间的推移，每次看到的视觉图像存在许多差异。当视觉变化很重要时，先前对某张脸的熟悉程度可能会促进识别。我们利用事件相关功能磁共振成像技术，对13名健康观察者进行研究，在重复启动范式中，同一面孔的两张不同照片（无论是名人还是不熟悉的面孔）以不同的延迟重复出现，我们研究了在视觉外观发生变化时参与提取面孔身份的脑系统。我们发现，外侧梭状回中功能定义的面孔选择区域，无论面孔是否熟悉，在不同视角变化的面孔上均未表现出重复效应，这表明在该区域形成的面孔表征不会在不同视觉图像之间泛化，即使是对知名面孔也是如此。重复呈现不熟悉面孔的不同但易于识别的视角，会使右侧梭状回内侧部分出现选择性重复减少，而重复呈现名人面孔的不同视角，则会使左侧颞中回和左侧额下回皮质选择性地出现重复减少，但梭状回皮质没有减少。这些发现表明，在梭状面孔区域所支持的初始感知阶段，同一熟悉面孔的不同视角可能不会整合在单一表征中，而是涉及到后期的处理阶段，在这个阶段可以获取更抽象的身份信息。
