ABSTRACT
Purpose: The ability to hear ourselves speak has been shown to play an important role in the development and maintenance of fluent and coherent speech. Despite this, little is known about the developing speech motor control system throughout childhood, in particular if and how vocal and articulatory control may differ throughout development. A scoping review was undertaken to identify and describe the full range of studies investigating responses to frequency altered auditory feedback in pediatric populations and their contributions to our understanding of the development of auditory feedback control and sensorimotor learning in childhood and adolescence. Method: Relevant studies were identified through a comprehensive search strategy of six academic databases for studies that included (a) real-time perturbation of frequency in auditory input, (b) an analysis of immediate effects on speech, and (c) participants aged 18 years or younger. Results: Twenty-three articles met inclusion criteria. Across studies, there was a wide variety of designs, outcomes and measures used. Manipulations included fundamental frequency (9 studies), formant frequency (12), frequency centroid of fricatives (1), and both fundamental and formant frequencies (1). Study designs included contrasts across childhood, between children and adults, and between typical, pediatric clinical and adult populations. Measures primarily explored acoustic properties of speech responses (latency, magnitude, and variability). Some studies additionally examined the association of these acoustic responses with clinical measures (e.g., stuttering severity and reading ability), and neural measures using electrophysiology and magnetic resonance imaging. Conclusion: Findings indicated that children above 4 years generally compensated in the opposite direction of the manipulation, however, in several cases not as effectively as adults. Overall, results varied greatly due to the broad range of manipulations and designs used, making generalization challenging. Differences found between age groups in the features of the compensatory vocal responses, latency of responses, vocal variability and perceptual abilities, suggest that maturational changes may be occurring in the speech motor control system, affecting the extent to which auditory feedback is used to modify internal sensorimotor representations. Varied findings suggest vocal control develops prior to articulatory control. Future studies with multiple outcome measures, manipulations, and more expansive age ranges are needed to elucidate findings.
ABSTRACT
OBJECTIVE: This scoping review synthesizes the scholarly literature on cognitive communication impairments in traumatic brain injury (TBI) sustained during childhood to identify gaps in research, and make recommendations that will further the field of cognitive communication in pediatric TBI. METHODS: MEDLINE, PsycINFO, CINAHL, and EMBASE were searched to identify peer-reviewed studies that examined cognitive communication impairments in children who sustained a TBI between 3 months to 18 years of age. RESULTS: Twenty-eight studies met inclusion criteria with 3 main categories identified in relation to cognitive communication: (1) impairments according to TBI severity, (2) impairments according to age at injury, and (3) trends in recovery according to TBI severity. CONCLUSIONS: The results of this scoping review suggest that (1) TBI severity is not the sole predictor of performance; other factors contribute to cognitive communication outcome and recovery; (2) developing skills at time of injury are most susceptible to impairment; and (3) standard, norm-referenced language assessments are not sensitive in detecting language impairments that are secondary to cognitive impairments found in TBI. Directions for future research and suggestions for clinical practice are proposed.
