Kimura D, Watson N
University of Western Ontario, London, Canada.
Brain Lang. 1989 Nov;37(4):565-90. doi: 10.1016/0093-934x(89)90112-0.
A large series of neurological patients, selected solely on the basis that they had damage restricted to one hemisphere of the brain, was given a variety of tests of basic speech and praxic function. Within the left-damaged group, patients were further identified as aphasic or nonaphasic, based on preexisting standard tests of aphasia. Subgroups of aphasics were studied on the basis of lesion location, rather than on the basis of aphasia type. The focus of the study was the relation between the production of speech and nonspeech oral movements, particularly across anterior and posterior lesions. Reproduction of single nonverbal oral movements and of single isolated speech sounds was found to be very highly correlated, and both depended selectively on the left anterior region of the brain. This same region was critically important for rapid repeated articulation of a syllable, suggesting that it mediates control at some "unit" level of movement, in a phenomenological sense, for both speech and nonspeech movements. Other "speech" regions in the left hemisphere appeared to be dispensable for the production of single oral movements, whether these were verbal or nonverbal movements. However, for most aphasic patients, an area in the left posterior region was inferred to be essential for production of multiple oral movements, whether nonverbal or verbal, suggesting a critical role in the accurate selection of movements. Within the posterior region, there was further differentiation for multisyllabic speech into a parietal system, which appeared to mediate primarily praxic function, and a temporal system, which appeared to mediate verbal-echolalic function. Aphasias from anterior and posterior lesions resembled "Broca's" and "Wernicke's" aphasia only insofar as they differed in fluency, with anterior aphasics clearly less fluent. Tests of speech comprehension did not differentiate the groups. It is suggested that classifying aphasic patients via lesion location rather than aphasic typology might yield a view of functional subsystems different from those commonly accepted.
选取了一大组神经科患者，入选标准仅为他们的脑损伤局限于一侧大脑半球，并对其进行了各种基本言语和运用功能测试。在左侧脑损伤组中，根据已有的失语症标准测试，患者被进一步分为失语症患者和非失语症患者。对失语症患者亚组的研究是基于损伤位置，而非失语症类型。该研究的重点是言语和非言语口腔运动的产生之间的关系，特别是前部和后部损伤患者之间的关系。研究发现，单个非言语口腔运动和单个孤立语音的再现高度相关，且二者均选择性地依赖于大脑左侧前部区域。同一区域对于音节的快速重复发音至关重要，这表明从现象学角度来看，它在某种“单元”运动水平上介导了言语和非言语运动的控制。左半球的其他“言语”区域对于单个口腔运动的产生似乎并非必不可少，无论这些运动是言语性的还是非言语性的。然而，对于大多数失语症患者而言，左侧后部区域的一个区域被推断对于多种口腔运动（无论是非言语性还是言语性）的产生至关重要，这表明该区域在准确选择运动方面起着关键作用。在后部区域内，多音节言语进一步分化为一个顶叶系统和一个颞叶系统，顶叶系统似乎主要介导运用功能，颞叶系统似乎主要介导言语模仿功能。前部和后部损伤导致的失语症仅在流畅性方面有所不同，前部失语症患者明显更不流畅，这一点与“布罗卡”失语症和“韦尼克”失语症相似。言语理解测试并未区分这些组。研究表明，通过损伤位置而非失语症类型对失语症患者进行分类，可能会得出与普遍接受的功能子系统不同的观点。
