The Development of Left Hemisphere Lateralization for Sentence-Level Prosodic Processing.

PURPOSE: The fine-tuning of linguistic prosody in later childhood is poorly understood, and its neurological processing is even less well studied. In particular, it is unknown if grammatical processing of prosody is left- or right-lateralized in childhood versus adulthood and how phonological working memory might modulate such lateralization. Furthermore, it is virtually unknown how prosody develops neurologically among children with cochlear implants (CIs). METHOD: Normal-hearing (NH) children ages 6-12 years and NH adults ages 18-28 years completed a functional near-infrared spectroscopy neuroimaging task, during which they heard sentence pairs and judged whether the sentences did or did not differ in their overall prosody (declarative, question, with or without narrow focus). Children also completed standard measures of expressive and receptive language. RESULTS: Age group differences emerged; children exhibited stronger bilateral temporoparietal activity but reduced left frontal activation. Furthermore, children's performance on a nonword repetition test was significantly associated with activation in the left inferior frontal gyrus-an area that was generally more activated in adults than in children. CONCLUSIONS: The prosody-related findings are generally consistent with prior neurodevelopmental works on sentence comprehension, especially those involving syntax and semantics, which have also noted a developmental shift from bilateral temporal to left inferior frontal regions typically associated with increased sensitivity to sentence structure. The findings thus inform theoretical perspectives on brain and language development and have implications for studying the effects of CIs on neurodevelopmental processes for sentence prosody. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.22255996.

Acquisition of consonants among typically developing Akan-speaking children: A preliminary report.

PURPOSE: Although Akan is one of the most widely spoken indigenous languages in Ghana, very little is known about children's phonological development. This paper investigates the development of consonants in Akan among typically developing children aged 3-5 years. METHOD: A list of 103 Akan words was compiled, sampling the full range of prosodic structures, sound positions, features and segments, and controlling for word familiarity. A native Akan speaker audio-recorded the 103 single-word productions from each of nine typically developing children aged 3-5 years. The child productions were transcribed and analysed following procedures used in a larger cross-linguistic study. The current study presents results on the acquisition of consonants across the various ages. RESULT: Preliminary results indicate that most consonants in Akan are mastered by age 4 or 5, similar to reports for other languages, although /w/ and /l/ showed late mastery, contrary to cross-linguistic observations. The rhotic /ɹ/ and consonants with secondary articulation were still developing at age 4 and showing a variety of mismatch patterns across children. CONCLUSION: The findings provide preliminary information for developmentalists and speech-language pathologists on typical phonological development in Akan and contribute to a growing database on language acquisition in Niger-Congo languages.

U-shaped development in error-driven child phonology.

Phonological regressions or U-shaped development have frequently been observed in longitudinal studies of child speech production. However, the typology of which phonological patterns regress, and their implications for learning, have not been given much attention in the recent literature on constraint-based phonological development. One basic question is simply the definition of a phonological regression, as created by the grammar or other mechanisms, which is in turn dependent on the type of grammar and learner assumed. This paper systematically addresses the question of whether or not attested phonological regressions are incompatible with an error-driven approach to grammatical development, whereby each round of learning is predicted to move the learner closer to the target language. From this perspective, this survey discusses case studies of phonological regression in the literature, grouped according to their ease of explanation under error-driven learning. Three types are identified and exemplified: regressions which are easily explained with existing error-driven algorithms for constraint-reranking; regressions which can also be derived through error-driven learning by adopting an additional tool (for incorporating child-specific phonetic experience); and regressions whose error-driven motivation remains unclear. Another central theme of the survey is the degree of variation and lexical exceptionality among these regression patterns, and the extent to which such variability is captured in the learner's algorithms or grammar. Interim conclusions are provided, and necessary future directions for empirical and theoretical research are discussed. This article is categorized under: Linguistics > Language Acquisition Linguistics > Linguistic Theory.

Human central auditory plasticity: A review of functional near-infrared spectroscopy (fNIRS) to measure cochlear implant performance and tinnitus perception.

OBJECTIVE: Functional near-infrared spectroscopy (fNIRS) is an emerging noninvasive technology used to study cerebral cortex activity. Being virtually silent and compatible with cochlear implants has helped establish fNIRS as an important tool when investigating auditory cortex as well as cortices involved with hearing and language processing in adults and during child development. With respect to this review article, more recently, fNIRS has also been used to investigate central auditory plasticity following hearing loss and tinnitus or phantom sound perception. METHODS: Here, we review the currently available literature reporting the use of fNIRS in human studies with cochlear implants and tinnitus to measure human central auditory cortical circuits. We also provide the reader with detailed reviews of the technology and traditional recording paradigms/methods used in these auditory-based studies. RESULTS: The purpose of this review article is to summarize theoretical advancements in our understanding of the neurocognitive mechanisms underlying auditory processes and their plasticity through fNIRS research of human auditory performance with cochlear implantation and plasticity that may contribute to the central percepts of tinnitus. CONCLUSION: fNIRS is an emerging noninvasive brain imaging technology that has wide reaching application that can be applied to human studies involving cochlear implants and tinnitus. LEVEL OF EVIDENCE: N/A.