Functional organization of velar movements following jaw perturbation.
Item
-
Title
-
Functional organization of velar movements following jaw perturbation.
-
Identifier
-
AAI9417484
-
identifier
-
9417484
-
Creator
-
Kollia, Haralambia.
-
Contributor
-
Adviser: Katherine Safford Harris
-
Date
-
1994
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Health Sciences, Speech Pathology | Biology, Neuroscience
-
Abstract
-
One approach to understanding the control of speech motor actions is to identify the manner in which individual articulators are coordinated. Previous investigations of relative timing indicate that jaw, lips, and larynx are functionally constrained during bilabial closing. Similar coordination has been observed linking the jaw and lips with the tongue, and, recently, with the velum, providing evidence of temporal stability among functionally related articulators. The interpretation is that speech movements are not controlled independently, but rather globally, reflecting large scale vocal tract actions.;Mechanical perturbation of the articulators has been used to examine motor control principles underlying speech production. One common observation has been that if one member of a group of functionally related articulators is perturbed during articulation, the other members compensate. These response patterns reflect sensorimotor organization for speech, having implications for speech production theories. The present study examines functional organization in speech motor control as indexed by the relationships between the spatiotemporal responses of both anatomically remote and linked articulators, namely in velum, upper lip, and lower lip kinematics following jaw perturbation.;Subjects were fitted with mandibular prostheses allowing delivery of jaw-lowering, random perturbations during productions of the utterance /mabnab/, around the first vowel onset. Jaw, lip, and velar kinematics were recorded optoelectronically, simultaneously with the acoustic signal.;Consistent with previous results, perturbed utterances differed from control utterances in the spatiotemporal characteristics of articulatory kinematics. Generally, articulatory displacements and velocities increased with jaw perturbation. These changes often depended on the time of perturbation, in that they tended to increase with loads occurring closer to the acoustic vowel onset. Additionally, temporal intervals between articulatory events within and across articulators were affected significantly by the perturbations. Coordinative timing among lips, jaw, and velum was generally maintained following the perturbation. Variations in timing frequently depended on the temporal relations between the onset of the perturbation and that of the component speech event.;These findings suggest that, when functionally coordinated, the jaw, lips, and velum exhibit comparable sensorimotor organization. Velar responses to jaw perturbation were analogous to lip and jaw responses, indicating a rather global speech motor control mechanism.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
