Evidence for development of distinction of voice onset time in a child with left-hemisphere lesion
| Autor: | Hansen Lr, Chermak Gd, Seikel Ja, Paulson-Sebold K, Hargrove Pm |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Consonant
Male medicine.medical_specialty Language delay Experimental and Cognitive Psychology Audiology Lateralization of brain function Speech Acoustics Lesion Postoperative Complications Speech Production Measurement Vowel medicine Meningeal Neoplasms Humans Language Development Disorders Child Dominance Cerebral Cerebral Cortex Verbal Behavior Voice-onset time Infant medicine.disease Sensory Systems Hydrocephalus Child Preschool Voice Brain Damage Chronic medicine.symptom Psychology Meningioma Follow-Up Studies |
| Zdroj: | Perceptual and motor skills. 81(3 Pt 1) |
| ISSN: | 0031-5125 |
| Popis: | Summary.-Following surgery for partial removal of the posterior left hemisphere at 5 mo., voice onset time was assessed to 9; 11 yr. Left-hemisphere language function associated with voicing appeared subsumed by the right hemisphere. The speech motor act involves bihemispheric activation (41, but the dominant hemisphere is responsible for initiation (2). The voicing dstinction in stop consonants is receptively processed by the left hemisphere on the basis of voice onset time (VOT), the time between release of the consonant burst and the onset of the following vowel. This contrast is recognized by neonates and produced by children as young as two years of age (5). We report the role of neural plasticity (1) in development of voice onset time of a child with severely reduced language function following prehgual brain surgery. At five months of age "Adam" underwent partial removal of the posterior left hemisphere during surgery for a benign meningioma. CT scan showed lesioning consistent with left-hemisphere posterior cerebral artery infarction arising from surgery and hydrocephalus; right hemiparesis and speech1 language delay persist. During the course of speech/language therapy which began at 2;4 years, spontaneous speech samples were audiorecorded weekly and were acoustically analyzed at age 9;11 years. Adam's voicing contrast clearly developed between the ages of 5;6 and 7;6 years. The velar voicing contrast was firmly established at 5;6 years, followed by aIveolar and bilabial stops by 7;6 years. Considering the significant speech/language deficit, it appears that left-hemisphere language function associated with voicing was subsumed by the right hemisphere, an interpretation supported by Square, Aronson, and Hyman (3). We interpret these results cautiously because the lesion occurred prior to establishment of hernispheric dominance, leaving the possibility that Adam would have developed language function in the right hemisphere in absence of the insult. |
| Databáze: | OpenAIRE |
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