Delvenne Jean François, Seron Xavier, Coyette Françoise, Rossion Bruno
Faculté de Psychologie et des Sciences de l'Education (PSP), Unité de Neurosciences Cognitives (NESC), Université Catholique de Louvain, Place du Cardinal Mercier 10, B-1348, Louvain-la-Neuve, Belgium.
Neuropsychologia. 2004;42(5):597-612. doi: 10.1016/j.neuropsychologia.2003.10.008.
Associative visual agnosia is classically defined as normal visual perception stripped of its meaning [Archiv für Psychiatrie und Nervenkrankheiten 21 (1890) 22/English translation: Cognitive Neuropsychol. 5 (1988) 155]: these patients cannot access to their stored visual memories to categorize the objects nonetheless perceived correctly. However, according to an influential theory of visual agnosia [Farah, Visual Agnosia: Disorders of Object Recognition and What They Tell Us about Normal Vision, MIT Press, Cambridge, MA, 1990], visual associative agnosics necessarily present perceptual deficits that are the cause of their impairment at object recognition Here we report a detailed investigation of a patient with bilateral occipito-temporal lesions strongly impaired at object and face recognition. NS presents normal drawing copy, and normal performance at object and face matching tasks as used in classical neuropsychological tests. However, when tested with several computer tasks using carefully controlled visual stimuli and taking both his accuracy rate and response times into account, NS was found to have abnormal performances at high-level visual processing of objects and faces. Albeit presenting a different pattern of deficits than previously described in integrative agnosic patients such as HJA and LH, his deficits were characterized by an inability to integrate individual parts into a whole percept, as suggested by his failure at processing structurally impossible three-dimensional (3D) objects, an absence of face inversion effects and an advantage at detecting and matching single parts. Taken together, these observations question the idea of separate visual representations for object/face perception and object/face knowledge derived from investigations of visual associative (prosop)agnosia, and they raise some methodological issues in the analysis of single-case studies of (prosop)agnosic patients.
联想性视觉失认症的经典定义是，正常的视觉感知失去了其意义[《精神病学与神经疾病档案》21卷（1890年）22页/英文译文：《认知神经心理学》5卷（1988年）155页]：这些患者无法利用其存储的视觉记忆对虽被正确感知但却无法归类的物体进行识别。然而，根据一种有影响力的视觉失认症理论[法拉赫，《视觉失认症：物体识别障碍及其对正常视觉的启示》，麻省理工学院出版社，马萨诸塞州剑桥，1990年]，视觉联想性失认症患者必然存在感知缺陷，这是他们在物体识别方面受损的原因。在此，我们报告了对一名双侧枕颞叶病变患者的详细研究，该患者在物体和面部识别方面严重受损。NS在临摹绘画方面表现正常，在经典神经心理学测试中使用的物体和面部匹配任务中也表现正常。然而，当使用精心控制的视觉刺激并同时考虑其准确率和反应时间，通过多项计算机任务对NS进行测试时，发现他在物体和面部的高级视觉处理方面表现异常。尽管他表现出的缺陷模式与之前在诸如HJA和LH等整合性失认症患者中所描述的不同，但其缺陷的特征是无法将各个部分整合为一个完整的感知，这从他在处理结构上不可能的三维（3D）物体时失败、不存在面部倒置效应以及在检测和匹配单个部分方面具有优势可以看出。综上所述，这些观察结果对源于视觉联想性（面孔）失认症研究的物体/面部感知与物体/面部知识的单独视觉表征这一观点提出了质疑，并且在分析（面孔）失认症患者的单病例研究时引发了一些方法论问题。
