Journal

The Japanese journal of neuropsychology

[Vol.20 No.1 contents]
Japanese/English

Full Text of this Article
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ArticleTitle Auditory perception and cognition of brain-damaged patients with auditory extinction in dichotic listening
Language J
AuthorList Chie Yoshikawa1), Tsuneo Harashima2), Akiyoshi Katada3)
Affiliation 1) Department of Speech and Hearing Sciences, International University of Health and Wealfare
2) Institute of Disability Sciences, University of Tsukuba
3) Department of Social Work Kinjo University
Publication Japanese Journal of Neuropsychology: 20 (1), 63-69, 2004
Received Sep 16, 2003
Accepted Nov 26, 2003
Abstract The present study investigated the nature of auditory extinction in 11 patients with brain damage by analyzing how they heard words in a dichotic listening test (DLT). The patients underwent DLT in the ordinary 'divided attention' condition (condition D) and the 'focused attention' condition (condition F) in which they paid attention to stimuli given to the right or left ear. After DLT, the patients were asked how they heard the words according to the following questions: "How many words did you hear in each trial?" and "Which ear did you hear the word (s) from?"
It was found that all patients had auditory extinction, because they could not report any words presented to the ear contralateral to the lesion side in the DLT. Never the less, the reports of what they heard varied. The results showed auditory extinction is a phenomenon including many subtypes. We classified all patients into four groups by attention condition. Group 1 asserted that they could not hear only a single stimulus to the ear contralateral to the lesion side, just as in condition F. Group 2 could perceive two stimuli but heard them only very faintly with the ear contralateral to the lesion side. This phenomenon was called obscuration. We regarded it not as a different phenomenon but as a part of auditory extinction. Group 3 could not hear a single stimulus to the ear contralateral to the lesion side, but could hear it during condition F. Paying attention with one ear was effective and related to top-down processing in an auditory processing disorder regarding stimuli. Group 4 could not hear a single stimulus to the ear contralateral to the lesion side, but reported the stimulus presented at the ear ipsilateral to the lesion if they directed their attention to the right or left ear in condition F. It was thought that they heard with both ears a stimulus presented to one ear. They were not aware they had a hearing problems, so it was thought that their results were affected by cognitive disorders such as a space cognitive disorder.
Thus, to understand the hearing of patients, one must analyze the perceptual condition of the patient in addition to determining auditory extinction by performance on the DLT.
Keywords auditory extinction, auditory perception and cognition, dichotic listening

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