The Japanese journal of neuropsychology

Full Text of this Article
in Japanese PDF (327K)

ArticleTitle	On the origin of occasional utterances in global aphasia
Language	J
AuthorList	Minoru Matsuda
Affiliation	Department of Behavioral Neurology and Cognitive Neuroscience, Tohoku University Guraduate School of Medicine
Publication	Japanese Journal of Neuropsychology: 30 (3), 176-184, 2014
Received
Accepted
Abstract	John Hughlings Jackson described recurring and occasional utterances as characteristic verbal outputs in severely affected aphasics. According to his theory of the principle of automatico-voluntary dissociation, severely affected aphasics lose intellectual language but preserve emotional language. While intellectual language is characterized as propositional and voluntary, its counterpart, emotional language is non-propositional linguistic performance that emerges involuntarily and automatically. Jackson hypothesized that recurring and occasional utterances are the prototype of automatic speech, and that they originate from the activity of right cerebral hemisphere. To explore the origin of, and the pathophysiological mechanisms underlying occasional utterances, various types of research concerning the automatic speech have been made including studies of behavioral observation of verbal outputs in aphasics compared with normal individuals or right-hemisphere-damaged patients, rCBF studies during the automatic speech, and neuropsychological case studies relevant to automatico-voluntary dissociation. The evidence thus obtained does not reach a conclusion that automatic speech is a product of the right hemisphere. Furthermore, according to my experiences, a severe disruption of propositional language is often accompanied by comparable disturbances of automatic speech. Therefore, the right hypothesis of right hemisphere contribution is not so robust. To elucidate the pathogenesis of occasional utterances, the possibility that they originate from the neuronal system other than the right hemisphere, for example, residual activity of damaged left hemisphere, basal ganglia, or limbic systems, should be considered.
Keywords	automatico-voluntary dissociation, occasional utterances, automatic speech, non-propositional speech, right hemisphere hypothesis