Ignatius S. B. Nip

Early speech motor development: Cognitive and linguistic considerations

UNLABELLED This longitudinal investigation examines developmental changes in orofacial movements occurring during the early stages of communication development. The goals were to identify developmental trends in early speech motor performance and to determine how these trends differ across orofacial behaviors thought to vary in cognitive and linguistic demands (i.e., silent spontaneous movements, babble, and first words). Movements of the lower lip and jaw were recorded using a three-dimensional motion capture system. Twenty-four infants were observed every 3 months, from 9 to 21 months of age. Jaw and lower lip speed, and lower lip range of movement increased with age. Silent spontaneous movements were consistently slower than words, whereas kinematic measures associated with babble did not differ from those associated with words. These findings suggest that speech movements may reflect linguistic and cognitive processing demands and that the continuity hypothesis between babbling and words may also be observed at the kinematic level. LEARNING OUTCOMES Readers will be able to: (1) describe the potential role of cognition and language in early speech development, (2) describe kinematic changes in the orofacial system from 9 to 21 months of age, and (3) identify the differences in kinematic characteristics for silent spontaneous orofacial movements, babbles and words between 15 to 21 months of age.

The co-emergence of cognition, language, and speech motor control in early development: A longitudinal correlation study

UNLABELLED Although the development of spoken language is dependent on the emergence of cognitive, language, and speech motor skills, knowledge about how these domains interact during the early stages of communication development is currently limited. This exploratory investigation examines the strength of associations between longitudinal changes in articulatory kinematics and development of skills in multiple domains thought to support early communication development. Twenty-four children were investigated every 3 months between the ages of 9 and 21 months. Movements of the upper lip, lower lip, and jaw were transduced using a three-dimensional motion capture system to obtain age-related changes in movement speed and range of movement. Standardized measures of cognition and language from the Battelle Developmental Inventory, 2nd edition and the MacArthur-Bates Communicative Development Inventory were also collected. Significant associations were identified between orofacial kinematic and the standardized measures of language and cognitive skills, even when age served as covariate. These findings provide preliminary evidence of interactions between cognition, language, and speech motor skills during early communication development. Further work is needed to identify and quantify causal relations among these co-emerging skills. LEARNING OUTCOMES The reader will be able to: (1) describe how cognition, language, and speech motor control may interact during speech development, (2) describe the associations between speech kinematic characteristics and measures of cognition and language.

Breath Group Analysis for Reading and Spontaneous Speech in Healthy Adults

Aims: The breath group can serve as a functional unit to define temporal and fundamental frequency (f₀) features in continuous speech. These features of the breath group are determined by the physiologic, linguistic, and cognitive demands of communication. Reading and spontaneous speech are two speaking tasks that vary in these demands and are commonly used to evaluate speech performance for research and clinical applications. The purpose of this study is to examine differences between reading and spontaneous speech in the temporal and f₀ aspects of their breath groups. Methods: Sixteen participants read two passages and answered six questions while wearing a circumferentially vented mask connected to a pneumotach. The aerodynamic signal was used to identify inspiratory locations. The audio signal was used to analyze task differences in breath group structure, including temporal and f₀ components. Results: The main findings were that spontaneous speech task exhibited significantly more grammatically inappropriate breath group locations and longer breath group duration than did the passage reading task. Conclusion: The task differences in the percentage of grammatically inadequate breath group locations and in breath group duration for healthy adult speakers partly explain the differences in cognitive-linguistic load between the passage reading and spontaneous speech.

Proficiency and Linguistic Complexity Influence Speech Motor Control and Performance in Spanish Language Learners.

PURPOSE Second-language (L2) production requires greater cognitive resources to inhibit the native language and to retrieve less robust lexical representations. The current investigation identifies how proficiency and linguistic complexity, specifically syntactic and lexical factors, influence speech motor control and performance. METHOD Speech movements of 29 native English speakers with low or high proficiency in Spanish were recorded while producing simple and syntactically complex sentences in English and Spanish. Sentences were loaded with cognate (e.g., baby-bebé) or noncognate (e.g., dog-perro) words. Effects of proficiency, lexicality (cognate vs. noncognate), and syntactic complexity on maximum speed, range of movement, duration, and speech movement variability were examined. RESULTS In general, speakers with lower L2 proficiency differed in their speech motor control and performance from speakers with higher L2 proficiency. Speakers with higher L2 proficiency generally had less speech movement variability, shorter phrase durations, greater maximum speeds, and greater ranges of movement. In addition, lexicality and syntactic complexity affected speech motor control and performance. CONCLUSIONS L2 proficiency, lexicality, and syntactic complexity influence speech motor control and performance in adult L2 learners. Information about relationships between speech motor control, language proficiency, and cognitive-linguistic demands may be used to assess and treat bilingual clients and language learners.

Phonetic equivalence in the acquisition of / l / by Spanish–English bilingual children

Spanish [l] is characterized as clear, and is associated with a high second formant (F2) frequency and a large difference between F2 and the first formant (F1) frequencies. In contrast, English [l] is darker (with a lower F2 and a relatively smaller F2–F1 difference) and also exhibits contextual variation due to an allophonic velarization rule that further darkens [l] postvocalically. We aimed to determine if Spanish–English bilingual children evidence these differences productively, in a manner comparable to that of monolinguals, or if they produce an [l] that is intermediate to that of Spanish and English monolinguals. We acoustically analyzed [l] productions of seven Spanish–English bilingual, seven Spanish monolingual, and seven English monolingual children. Results showed that the bilinguals had similar prevocalic F2 and F2–F1 values for [l] in both languages, comparable to those of Spanish monolinguals, but significantly higher than those of English monolinguals. The bilinguals also produced English (but not Spanish) [l] with significantly lower postvocalic F2 and F2–F1 values. We assume that the bilinguals have a merged phonetic category for prevocalic [l] but not postvocalic [l], and further, that they maintain separate grammars, allowing the allophonic velarization rule to apply in English but not Spanish.

Interarticulator coordination in children with and without cerebral palsy

Abstract The current study investigates how interarticulator coordination changes across speaking tasks varying in articulatory and linguistic demands for children with CP and their typically-developing peers. Articulatory movements from 12 children with spastic CP (7M, 5F, 4–15 years of age) and 12 typically-developing age- and sex-matched peers were cross-correlated to determine the degree of spatial and temporal coupling between the upper lip and jaw, lower lip and jaw, and upper and lower lips. Spatial and temporal coupling were also correlated with intelligibility. Results indicated that children with CP have reduced spatial coupling between the upper and lower lips and reduced temporal coupling between all articulators as compared to their typically-developing peers. For all participants, sentences were produced with the greatest degree of interarticulator coordination when compared to the diadochokinetic and syllable repetition tasks. Measures of interarticulator coordination were correlated with intelligibility for the speakers with CP.

Accuracy of perceptually based and acoustically based inspiratory loci in reading

Investigations of speech often involve the identification of inspiratory loci in continuous recordings of speech. The present study investigates the accuracy of perceptually determined and acoustically determined inspiratory loci. While wearing a circumferentially vented mask connected to a pneumotach, 16 participants read two passages. The perceptually determined and acoustically determined inspiratory loci were compared with the actual loci of inspiration, which were determined aerodynamically. The results showed that (1) agreement across all three judges was the most accurate of the approaches considered here for detecting inspiratory loci based on listening; (2) the most accurate pause duration threshold for detecting inspiratory loci was 250 msec; and (3) the perceptually based breath-group determination was more accurate than the acoustically based determination of pause duration. Inconsistencies among perceptually determined, acoustically determined, and aerodynamically determined inspiratory loci are not negligible and, therefore, need to be considered when researchers design experiments on breath groups in speech.

Cognitive and linguistic influences on speech motor development

Speech development is affected by the interaction of the development of various domains, including motor control and language. Infants demonstrate strong associations between speed and range of movement of the lips and jaw with cognitive (attention, memory) and language (number of words understood/expressed, number of gestures used) skills during language acquisition (Nip et al., 2011). In addition, goal-directed vocal behaviors (e.g., words) are produced with faster lip and jaw speeds in infants (Nip et al., 2009). Similar task-related changes can be observed in older children. Tasks requiring greater language formulation demands (e.g., re-telling stories) are produced with greater movement speeds and oral excursions than tasks requiring fewer demands (e.g., repeating syllables) (Nip & Green, 2013). Kinematic descriptions of speech production may provide insight into the acoustic consequences of adapting movement strategies for different tasks; increasing oral excursions may be a strategy to increase art...

Articulatory exaggerations during infant directed speech

Although a growing body of literature suggests a principal role for observational learning in the acquisition of speech, the facial movements of infant directed speech (IDS) have rarely been studied. Identifying both the auditory and visual features of IDS is an essential step toward understanding the contribution of environmental stimulation to the development of speech and language. The current project uses three‐dimensional motion capture technology to describe how parents modify their articulatory movements when communicating with their infants. The following three experimental questions will be addressed: (1) Do parents exaggerate articulatory gestures during IDS?; (2) If so, are there individual differences among parents in the degree of IDS?; and (3) Is there a strong association between acoustic and movement characteristics of IDS? Mouth movements were recorded from twenty‐four mothers while speaking to their infants and to an unfamiliar adult. Mouth shapes during four target vowels were measured ...