Viewpoint of understanding aphasia for better rehabilitation

Abstract

We need to understand aphasia in terms of two points of view. One is the viewpoint of system of language, and the other is the viewpoint of brain function. Language systems are hierarchically constructed, for instance, acoustic system (hearing and speech), phonetic system (discrimination of language sounds and articulation control), phonemic system and lexical/semantic system. Language impairments can be developed of each system as language symptoms. And there are corresponding lesion sites in the brain for each elementary language symptoms such as anarthrie/apraxia of speech, impairment of discrimination of language sound (word deafness), phonemic paraphasia, word comprehension impairment, word retrieval impairment and so on. Classical aphasia classification are vascular syndromes and can be explained as the syndromes made of the elementary symptoms.