[Aphasia--a new as well as old problem].

Alajouanine (1956) established a concept of jargon as a speech symptom of aphasia and gave clinical descriptions of three types of jargon-undifferentiated, asemantic (neologistic) and paraphasic (semantic) jargon. Several case-reports of undifferentiated jargon in Japanese language have been published in clinical aphasiology. On the other hand language development of jargon-type in normal children was reprorted in developmental psychology. We point out a phenomenological similarity of clinical language symptoms of jargon with language development of jargon-type considering its neuropsychological implications.