Motor Speech Deficits Research Articles

Reliability of labial closure force measurements in normal subjects and patients with CNS disorders.

This study determined the reliability of maximal upper and lower lip closing forces measured using a strain-gauged cantilever beam assembly. An intraclass correlation approach was used to explicitly partition the "error free" between-subject variance and measurement error variance across repeated days (2) and across repeated trials (5). Ten healthy adults served as controls and 30 patients with diagnoses of multiple sclerosis, cerebrovascular accident, or Parkinson's disease served as subjects. The intraclass correlation analyses revealed generally high reliability (R greater than .90) for upper and lower lip force measurements, for various combinations of control and/or patient groups, and within each individual patient group. There was moderate correspondence between the quantitative measures of lip force and the clinical assessment of combined upper (r = .67) and lower lip closure force (r = .62) but low correspondence between the quantitative measures of lip force and the presence of motor speech deficit. The lower lip force of patients with Parkinson's disease (M = 3.1 N) on Day 1 was markedly reduced from that of all other patient groups and controls (M = 10.1 N). These results yield helpful information for the design of investigations of oral-motor weakness and for the quantitative assessment of an individual's clinical status.

Taxonomies in Biology, Phonetics, Phonology, and Speech Motor Control

This article begins with a review explaining the different purposes of biological taxonomies. Taxonomic units are often dependent on the purpose for which the taxonomy has been constructed. Biological taxonomies provide an analogy that we use to emphasize some of the distinctions among the units of phonetic transcription systems, competence phonologies, and performance phonologies. The units of both phonology and phonetic transcription are considered as possible units of the speech motor system, and some of the difficulties of this assumption are explained. Although phonemic units, like units of phonetic transcription, are useful for many purposes, it is not theoretically necessary to use units derived as part of competence phonologies in systems attempting to explain phonological performance or speech motor performance. In this regard, we challenge the concept of coarticulation, because it is based on assumptions about the role of phonological or phonetic units in speech motor control. We offer an integrated perspective that has implications for research in speech motor control and deficits of the speech motor system. We see speech motor deficits as distinct from, yet possibly interacting with, phonological deficits.

The Timing of Syllable Repetitions in Developmental Dyslexia

The temporal organization of motor speech was examined in dyslexic adolescents and adults without overt speech difficulties, matched normal readers, and learning disabled adolescents without reading difficulties. Subjects were asked to repeat nonsense two- and three-syllable strings in time to each of four metronome speeds. Speech samples were analyzed for repetition rates, time coherence between prescribed and actual performance, and serial ordering of three-syllable strings. Dyslexic subjects deviated more from the prescribed rate, repeated syllables too slowly at all metronome speeds, and made more speech sequencing errors than normal or learning disabled controls. Repetition rate and syllable sequencing contributed as independent variables to the temporal organization of motor speech. The relevance of motor speech deficits for reading impairment in dyslexia is discussed.

Visual symbol and manual sign learning by children with phonologic programming deficit syndrome.

A study was done of eight children with phonologic programming deficit syndrome (PPDS) and of eight normally developing children, to evaluate learning and recall of Blissymbols and of Signed English manual signs. The results support the view that children with this syndrome not only have motor speech deficits, but also deficits in symbolic processing. Decisions about intervention for nonverbal children should take account of their probable deficits in symbol learning.

Motor speech deficit following carotid endarterectomy.

Stroke as a complication of carotid endarterectomy has been extensively reviewed. Considerably less attention has been directed to local injuries of the cranial nerves and their branches. Verta, Hertzer, Imparato, DeWeese, and Matsumoto have reported experience with these injuries. DeWeese found a 9.7% rate of cranial nerve injury, while in Hertzer's series, 15% of patients had nerve dysfunction in the early postendarterectomy period. In 1980, Liapis in a preliminary report found that when postoperative examination was supplemented by detailed evaluation by speech pathologists, the incidence of early abnormalities reached 27%. The purpose of this study was to expand upon Liapis' early observation and to clarify the contribution of the speech pathologists in identifying cranial nerve dysfunctions, specifically those resulting in motor speech abnormalities, following carotid endarterectomy.