COGNITIVE AND NEURAL MECHANISMS UNDERLYING VISUAL AND SEMANTIC PROCESSING - IMPLICATIONS FROM OPTIC APHASIA
COGNITIVE AND NEURAL MECHANISMS UNDERLYING VISUAL AND SEMANTIC PROCESSING - IMPLICATIONS FROM OPTIC APHASIA
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DOI：
10.1162/jocn.1995.7.4.457
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发表时间：
1995-09-01
影响因子：
3.2
通讯作者：
CARAMAZZA, A
中科院分区：
文献类型：
--
作者：
HILLIS, AE;CARAMAZZA, A
我们报告的详细分析的性能的病人，DHY，谁作为中风的结果，在左枕叶和脑室周围的白色物质在该地区的压部，表现出严重受损的命名视觉刺激，尽管幸免于识别视觉刺激和幸免于命名在其他方式。这种被称为“视性失语”的表现模式，以前被解释为支持存在独立的语义系统的假设，即视觉和言语语义存储（Beauvois，1982年; Lhermitte Sr Beauvois，1973）或右半球和左半球语义系统（Coslett & Saffran，1989，1992），在这些患者中，它们是“断开的”。我们提供的证据表明，DHY精确地显示了各种语言和视觉任务的表现类型，这些任务被用来支持这些独立语义系统的主张：（1）在对定义的命名和为触觉探索呈现的物体命名方面表现良好（这被解释为言语或左半球语义处理的证据），以及（2）在各种不需要命名的“语义”任务中表现良好（这被解释为获得备用视觉或右半球语义处理）。然而，当非语言语义任务被修改，他们需要访问更多的出轨语义信息的准确性能，DHY是准确得多，这表明她没有访问完整的语义信息的对象在视觉模态。我们认为，这些数据削弱了声称，视性失语症的情况下，只能通过提出多个语义系统来解释。我们提出了一个替代帐户这种模式的性能，在一个模型的视觉对象命名，指定一个单一的，模态独立的语义系统。我们表明，DHY和其他“视性失语症”患者的表现可以解释为提出一个赤字，在访问一个完整的，独立于模态，词汇语义表示从一个完整的存储，结构描述的对象。我们讨论了这些结论的语义和视觉对象处理的神经解剖学相关索赔的影响。
We report detailed analyses of the performance of a patient, DHY,who as a consequence of strokes in the left occipital lobe and the periventricular white matter in the region of the splenium, showed severely impaired naming of visual stimuli despite spared recognition of visual stimuli and spared naming in other modalities. This pattern of performance-labeled ''optic aphasia''-has been previously interpreted as support for the hypothesis that there are independent semantic systems, either a visual and a verbal semantic store (Beauvois, 1982; Lhermitte Sr Beauvois, 1973) or a right hemisphere and a left hemisphere semantic system (Coslett & Saffran, 1989, 1992), which are ''disconnected'' in these patients. We provide evidence that DHY shows precisely the types of performance across a variety of verbal and visual tasks that have been used to support these claims of separate semantic systems: (1) good performance in naming to definition and naming objects presented for tactile exploration (which has been interpreted as evidence of spared verbal or left hemisphere semantic processing), and (2) good performance on various ''semantic'' tasks that do not require naming (which has been interpreted as access to spared visual or right hemisphere semantic processing). Nevertheless, when nonverbal semantic tasks were modified such that they required access to more derailed semantic information for accurate performance, DHY was far less accurate, indicating that she did not access complete semantic information about objects in the visual modality. We argue that these data undermine the claim that cases of optic aphasia can be explained only by proposing multiple semantic systems. We propose an alternative account for this pattern of performance, within a model of visual object naming that specifies a single, modality-independent semantic system. We show that the performance of DHY and other ''optic aphasic'' patients can be explained by proposing a deficit in accessing a complete, modality-independent, lexical-semantic representation from an intact stored, structural description of the object. We discuss the implications of these conclusions for claims about the neuroanatomical correlates of semantic and visual object processing.