Yoko Fukusako

Voice onset time characteristics in apraxia of speech

Abstract In order to examine the timing control of laryngeal and supralaryngeal articulatory adjustments in apraxia of speech, voice onset time (VOT) data for stop consonants in monosyllables /de/, /te/, /ge/ and /ke/ were obtained from four apraxic subjects and compared with those of fluent aphasic and normal (both young and aged) speakers (Experiment 1). The results indicated that the VOT distribution patterns of the apraxic patients differed markedly from those of the other speakers. A second experiment was conducted to determine whether the VOT distribution patterns of these four apraxic patients and of two normal controls would change with a lapse of time (Experiment 2). The results of the second experiment demonstrated marked changes in the VOT distribution patterns over time in half of the apraxic patients examined, but essentially no change in the normal controls.

Speech sound errors in patients with conduction and Broca's aphasia ☆

Speech sound errors exhibited by three conduction and three Brocas aphasic patients on naming and word-repetition tasks were subjected to phonemic and subphonemic analyses. In the conduction aphasic patients, errors occurred equally often on consonants and vowels in both the naming and word-repetition tasks, while in the Brocas aphasic patients errors occurred selectively on consonants. Transposition errors occurred almost as often as substitution errors in the conduction aphasic patients, while substitution errors constituted the majority of errors in the Brocas aphasic patients. The Brocas aphasic patients, as compared to the conduction aphasic patients, exhibited a markedly higher number of substitution errors occurring between phonemes separated by a single subphonemic feature on the naming task. On the basis of these findings, it was hypothesized that the differences in the error patterns of the two types of aphasia reflected differences in the underlying mechanisms of the impairment in each type.

Internal representations and the conceptual operation of color in pure alexia with color naming defects

This research examined the structure of internal representation and the conceptual operation of color in two pure alexic cases (Case I and Case II) with color naming defects. Experiment I investigated the structure of the internal representation of different kinds of colors using a similarity judgment task. Experiment II examined categorical judgments of perceived colors using a two-alternative-forced choice task. Experiment III tested the classification of perceived colors using a color sorting task. The performance of Case I essentially fell within the normal range while the results of Case II showed some impairment in the conceptual operation of color. Analysis of the responses obtained from these experiments indicated that the color naming defects in Case I can be explained in terms of visual-verbal disconnection. However, the naming defects in Case II reflect disfunction in some other higher cortical processes coupled with visual-verbal disconnection.

Voice onset time perception in Japanese aphasic patients.

This study examines identification of the synthetic speech stimuli [ga] and [ka] of varying voice onset times (VOTs) in 17 Japanese aphasic subjects. Approximately two-thirds of the aphasic subjects showed deterioration in performance of VOT identification of the stimuli. A quantitative analysis of the results indicates that the problems of the majority of these subjects may be attributable not only to difficulty in labeling the stimuli but also to difficulty in processing the acoustic and/or phonetic information of the stimuli.

Recovery process of colour naming defects in pure alexia - A five year longitudinal experimental study

Abstract The present study investigated the recovery process of colour naming defects and the ability for matching seen colour to colour name given verbally (colour pointing) in a patient with pure alexia (M.S.). The recovery process of the patients ability to process the physical parameters involved in colour information processing was also examined. To look at how M.S. processed the physical parameters, the similarity judgment tasks of internal representation of colour generated by verbal and visual stimuli were employed. While colour pointing ability became practically normal 22 months postonset, colour naming defects took longer to recover. The analysis of the results of similarity judgment using multidimensional scaling revealed that : (1) verbal stimuli generated consistently more stable internal representation of colour than visual stimuli; and (2) colour information processing of M.S. altered ???hue with lightness??? dependent to more ???hue??? dependent in the 5 years since the onset of illness. The und...

Lexical semantic memory and confrontation naming in aphasic patients

Abstract The present study examined (1) the relation between semantic processing and confrontation naming abilities in aphasic patients, and (2) the possibility of the existence of separate semantic organizations for different stimulus modes. Semantic processing ability of the patients was investigated using similarity judgements of body parts represented by line drawings and kanji. One hundred line drawings were used for assessing confrontation naming ability. Both semantic processing and confrontation naming were studied on a single subject basis. The results showed that semantic processing and naming abilities were dissociated, indicating that these processes can be independently impaired. The underlying mechanism for the dissociation was discussed. Some patients showed better semantic judgment in the line drawings than in kanji but the reverse pattern was not observed. We interpreted this differential performance not as evidence supporting the existence of separate semantic organizations for line draw...

Characteristics of Dysarthric Speech in Unilateral Cerebral Lesions

一側性大脳半球病変における麻痺性 (運動障害性) 構音障害患者26例 (左大脳半球病変群14例, 右大脳半球病変群12例) および, 正常者13例の発話サンプルについて, 5名の評定者が, 聴覚印象に基づき評価した結果, 以下の知見が得られた.1) 今回対象とした麻痺性構音障害群における評価成績は, 正常群とは明らかに異なっており, 話しことばの障害があると判定されたが, 障害の程度は全般に軽度であった.2) 障害の特徴は, 仮性球麻痺と類似していたが, 重症度など異なる面もみられた.3) 障害側を比較すると, 概して左大脳半球病変群の方が重度の障害を示した.4) 病変の大きさと話しことばの重症度との関係は, 明らかではなかった.5) 従来, 大脳半球病変による麻痺性構音障害は, 病変が両側性の場合に出現するとされていたが, 今回の結果は一側性病変でも出現し得るということを示唆するものであった.