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Agraphia is an acquired neurological disorder causing a loss in the ability to communicate through writing, either due to some form of motor dysfunction〔 or an inability to spell.〔 The loss of writing ability may present with other language or neurological disorders;〔 disorders appearing commonly with agraphia are alexia, aphasia, dysarthria, agnosia, and apraxia.〔〔 The study of individuals with agraphia may provide more information about the pathways involved in writing, both language related and motoric.〔 Agraphia cannot be directly treated, but individuals can learn techniques to help regain and rehabilitate some of their previous writing abilities. These techniques differ depending on the type of agraphia. Agraphia can be broadly divided into central and peripheral categories. Central agraphias typically involve language areas of the brain, causing difficulty spelling or with spontaneous communication, and are often accompanied by other language disorders.〔 Peripheral agraphias usually target motor and visuospatial skills in addition to language and tend to involve motoric areas of the brain, causing difficulty in the movements associated with writing.〔 Central agraphia may also be called aphasic agraphia as it involves areas of the brain whose major functions are connected to language and writing; peripheral agraphia may also be called nonaphasic agraphia as it involves areas of the brain whose functions are not directly connected to language and writing (typically motor areas).〔 The history of agraphia dates to the mid-fourteenth century, but it was not until the second half of the nineteenth century that it sparked significant clinical interest. Research in the twentieth century focused primary on aphasiology in patients with lesions from strokes.〔 ==Characteristics== Agraphia or impairment in producing written language can occur in many ways and many forms because writing involves many cognitive processes (language processing, spelling, visual perception, visuospatial orientation for graphic symbols, motor planning, and motor control of handwriting).〔 Agraphia has two main subgroupings: central ("aphasic") agraphia and peripheral ("nonaphasic") agraphia. Central agraphias include lexical, phonological, deep, and semantic agraphia. Peripheral agraphias include allographic, apraxic, motor execution, hemianoptic and afferent agraphia.〔 〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Agraphia」の詳細全文を読む スポンサード リンク
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