title: Spatial and temporal lingual coarticulation and motor control in preadolescents.
abstract: PURPOSE In this study, the authors compared coarticulation and lingual kinematics in preadolescents and adults in order to establish whether preadolescents had a greater degree of random variability in tongue posture and whether their patterns of lingual coarticulation differed from those of adults. METHOD High-speed ultrasound tongue contour data synchronized with the acoustic signal were recorded from 15 children (ages 10-12 years) and 15 adults. Tongue shape contours were analyzed at 9 normalized time points during the fricative phase of schwa-fricative-/a/ and schwa-fricative-/i/ sequences with the consonants /s/ and /ʃ/. RESULTS There was no significant age-related difference in random variability. Where a significant vowel effect occurred, the amount of coarticulation was similar in the 2 groups. However, the onset of the coarticulatory effect on preadolescent /ʃ/ was significantly later than on preadolescent /s/, and also later than on adult /s/ and /ʃ/. CONCLUSIONS Preadolescents have adult-like precision of tongue control and adult-like anticipatory lingual coarticulation with respect to spatial characteristics of tongue posture. However, there remains some immaturity in the motor programming of certain complex tongue movements.
authors.forename: Natalia
authors.initials: N
authors.lastname: Zharkova
authors.forename: Nigel
authors.initials: N
authors.lastname: Hewlett
authors.forename: William J
authors.initials: WJ
authors.lastname: Hardcastle
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Lickley
mesh_terms: D000293:Adolescent; D041923:Adolescent Development; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D002648:Child; D002657:Child Development; D004525:Efferent Pathways / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010700:Phonetics; D013060:Speech / Q000502:physiology*; D013061:Speech Acoustics; D014059:Tongue / Q000000981:diagnostic imaging / Q000254:growth & development* / Q000502:physiology*; D014463:Ultrasonography; D055815:Young Adult