Gordon Neil
Huntlywood, 3 Styal Road, Wilmslow SK9 4AE, UK.
Brain Dev. 2004 Apr;26(3):146-50. doi: 10.1016/S0387-7604(03)00128-1.
Forms of sign language have developed in a number of countries. American Sign Language, which originated from French signing, has been most extensively researched. As sign language is based on gestures executed in space and perceived visually it might be thought that it would mainly be a function of the right cerebral hemisphere when this is the non-dominant one. A number of studies are reviewed showing that sign language is a language in its own right and therefore, as with spoken language, its primary site of organization is in the dominant hemisphere. This does not mean that there is not a significant contribution from the other hemisphere with an interplay between the two. Each research project usually contributes some facet of knowledge apart from the main conclusions. These included the importance of distinguishing signs from gestures, the localization of different types of signing within the left dominant cerebral hemisphere, the fact that lesions of the right non-dominant hemisphere, although not causing a loss of signing will result in dyspraxia, and that aphasic symptoms of signing and speech are not modality dependant but reflected a disruption of language processes common to all languages. Examples are given of discoveries made by the use of the newer neuroradiological techniques such as functional magnetic resonance imaging and positron emission tomography, and no doubt these will lead to further advances in knowledge. The use of sign language in the treatment of patients with verbal aphasia is considered, especially of children with the Landau-Kleffner syndrome, but therapy of this kind can be used in children with delayed language development, and in other types of acquired aphasia at any age. Other methods of treatment than signing, such as cochlear implants may be increasingly used in the future, but it seems likely that sign language will continue to be a dominant feature in the deaf culture.
手语形式已在许多国家得到发展。源自法国手语的美国手语得到了最为广泛的研究。由于手语基于在空间中执行且通过视觉感知的手势，人们可能会认为，当右脑半球为非优势半球时，手语主要是右脑半球的功能。本文回顾了多项研究，这些研究表明手语本身就是一种语言，因此，与口语一样，其主要组织部位在优势半球。这并不意味着另一半球没有显著贡献，两者之间存在相互作用。每个研究项目通常除了主要结论外，还会贡献一些知识层面的内容。这些内容包括区分手势和手语的重要性、左优势大脑半球内不同类型手语的定位、右非优势半球损伤虽不会导致手语丧失但会导致失用症这一事实，以及手语和言语的失语症状并非依赖于模态，而是反映了所有语言共有的语言处理过程的中断。文中还给出了使用功能磁共振成像和正电子发射断层扫描等更新的神经放射学技术所取得发现的示例，毫无疑问，这些技术将带来知识上的进一步进步。本文还探讨了手语在治疗言语性失语症患者中的应用，尤其是对患有兰道 - 克莱夫纳综合征的儿童，但这种治疗方法也可用于语言发育迟缓的儿童以及任何年龄段的其他类型获得性失语症患者。未来可能会越来越多地使用除手语之外的其他治疗方法，如人工耳蜗植入，但手语似乎仍将是聋人文化中的一个主要特征。
