The physiological development of speech production has remained largely unexplored in spite of Us importance to understanding developmental speech disorders and to models of normal speech motor control. In theoretical models and clinical applications, speech coordination, like other complex motor behaviors, has been assumed to be derived from rhythmic, homeostatic, centrally patterned functions such as respiration, chewing, and sucking. This assumption has not been tested, and despite its intuitive appeal, might be doubted because of demonstrated differences between centrally patterned behaviors and speech production in adults (Moore, Smith, & Ringel, 1988). An empirical evaluation of this assumption has implications both for models of normal speech motor control and for the rationale underlying diagnosis and treatment of children with developmental speech disorders. The proposed Investigation of normally developing children contrasts the coordination of centrally patterned oral and respiratory behaviors with speech coordination. This contrast will provide a quantitative description of speech development in the context of well-understood motor behaviors. Physiological development of speech motor control in primary speech subsystems in young children (9-48 months of age) will be described using a cross-sectional (70 children) and longitudinal (20 children) design. Coordination of systems for respiratory drive, mandibular movement, phonation, and articulation will be quantified during speech and during automatic, rhythmic, non-speech behaviors such as chewing and resting breathing. Electromyographic (EMG), acoustic, and kinematic signals will be analyzed. Articulatory coordination and laryngeal control will be inferred from formant (F1 and F2) trajectories and fundamental frequency (f-o) contours. Relative timing of muscle activity will be quantified using correlational analysis of E G signals. Signal coherence arising from paired speech muscles will be computed in order to detect activity arising from a common neural source. Non-zero coherence within paired EMG signals has been shown to be an observable characteristic of rhythmic motor behaviors, including mastication and respiration, both of which are mediated by central pattern generators (CPGs) in many species. Developmental changes in the temporal and spectral characteristics of EMG signals will delineate the role of automatic, non-speech coordinative organization in speech maturation.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29DC000822-01A1
Application #
3461731
Study Section
Sensory Disorders and Language Study Section (CMS)
Project Start
1991-05-01
Project End
1996-04-30
Budget Start
1991-05-01
Budget End
1992-04-30
Support Year
1
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Type
Schools of Arts and Sciences
DUNS #
053785812
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Shriberg, Lawrence D; Lohmeier, Heather L; Strand, Edythe A et al. (2012) Encoding, memory, and transcoding deficits in Childhood Apraxia of Speech. Clin Linguist Phon 26:445-82
Shriberg, Lawrence D; Lohmeier, Heather L; Campbell, Thomas F et al. (2009) A nonword repetition task for speakers with misarticulations: the Syllable Repetition Task (SRT). J Speech Lang Hear Res 52:1189-212
Leader 3rd, J K; Boston, J R; Moore, C A (1998) A data dependent computer algorithm for the detection of muscle activity onset and offset from EMG recordings. Electroencephalogr Clin Neurophysiol 109:119-23
Green, J R; Moore, C A; Ruark, J L et al. (1997) Development of chewing in children from 12 to 48 months: longitudinal study of EMG patterns. J Neurophysiol 77:2704-16
Ruark, J L; Moore, C A (1997) Coordination of lip muscle activity by 2-year-old children during speech and nonspeech tasks. J Speech Lang Hear Res 40:1373-85
Moore, C A; Ruark, J L (1996) Does speech emerge from earlier appearing oral motor behaviors? J Speech Hear Res 39:1034-47