The present study compared the infant's tendency in the first year of life to produce clusters of particular vocal types (squeals, vocants, and growls) in typically developing (TD) and autistic ...infants. Vocal clustering provides evidence of vocal category formation and may establish a foundation for speech development. Specifically, we compared the extent of vocal clustering across outcome groups and age groups. We also examined the associations between the extent of vocal clustering and later outcomes at 2 years within the autistic group. Randomly selected 5-min segments (27,153 5-min segments total) from 1293 all-day home recordings from 103 TD infants and 44 autistic infants across the first year were humancoded (about 9.75 h of data coded per infant on average) to derive vocal clustering patterns. Fisher's exact tests were used to compare the occurrence of squeals versus vocants, as well as growls versus vocants, across coded segments. Infants in both groups demonstrated clear clustering patterns of squeals and growls across all age groups. The extent of vocal clustering in the autistic group did not correlate significantly with later language, repetitive behavior, or autism severity outcomes. These findings highlight the robustness of the systematic production of vocal categories across the first year of life. The similarity of the clustering patterns in the TD and autistic groups suggests that vocal category formation through active infant vocal exploration is a robust feature of early speech development.
•Cortical activity modulates motor behavior from early fetal age onwards.•At early age motor behavior is characterized by variation and limited adaptation.•A major transformation in motor development ...occurs at 3–4 months post-term.•Transformation coincides with subplate dissolution in sensory and motor cortices.•After 3–4 months post-term, movement variation starts to serve adaptation.
This review summarizes early human motor development. From early fetal age motor behavior is based on spontaneous neural activity: activity of networks in the brainstem and spinal cord that is modulated by supraspinal activity. The supraspinal activity, first primarily brought about by the cortical subplate, later by the cortical plate, induces movement variation. Initially, movement variation especially serves exploration; its associated afferent information is primarily used to sculpt the developing nervous system, and less to adapt motor behavior. In the next phase, beginning at function-specific ages, movement variation starts to serve adaptation. In sucking and swallowing, this phase emerges shortly before term age. In speech, gross and fine motor development, it emerges from 3 to 4 months post-term onwards, i.e., when developmental focus in the primary sensory and motor cortices has shifted to the permanent cortical circuitries. With increasing age and increasing trial-and-error exploration, the infant improves its ability to use adaptive and efficicient forms of upright gross motor behavior, manual activities and vocalizations belonging to the native language.
The current study examined the role of English-speaking instruction and motivation in learners' development of L2 speech comprehensibility and accentedess, over the course of an academic semester. ...Eighty-three college students enrolled in English classes in China completed a sentence reading task and a picture description task twice (pre-test and post-test), as well as a questionnaire for measuring their future selves (Papi et al., 2019). The collected speech samples were coded for comprehensibility and accentedness. t-test results indicated that after one semester of English-speaking instruction, the learners made statistically significant gains in both L2 speech measures. Hierarchical multiple regression results showed that Ideal L2 Self/Own positively predicted speech comprehensibility, and Ideal L2 Self/Other negatively predicted L2 speech accentedness. The results suggest that learners’ future L2 selves influence how they take advantage of instructional opportunities to improve their L2 speech in qualitatively different manners. Theoretical and practical implications are discussed.
Objective::
The current study examined stop consonant production in children with cleft lip and/or palate (CP ± L) 2-6 months following palatal surgery.
Design::
Prospective comparative study.
...Setting::
Multisite institutional.
Participants::
Participants included 113 children with repaired CP ± L (mean age = 16 months) who were participating in the multicenter CORNET study.
Procedures:
Parents of participants were asked to record approximately two hours of their child's vocalizations/words at home using a Language ENvironmental Analysis (LENATM) recorder. Four ten-minute audio-recorded samples of vocalizations were extracted from the original recording for each participant and analyzed for presence of oral stop consonants. A minimum of 100 vocalizations were required for analysis.
Results::
Preliminary findings indicate that at least one oral stop was evident in the consonant inventory for 95 of the 113 children (84%) at the time of their post-surgery 16-month recording, and 80 of these children (71%) were producing two or more different stops. Approximately 50% of the children (57/113) produced the three voiced stops, and eight of the children (7%) were producing all six stop consonants.
Conclusions::
The findings of this study suggest that the majority of children with repaired CP ± L from English-speaking homes are producing oral stops within six months following palatal surgery. Similar to same-age children without CL ± P, voiced stops were more frequently evident in the children's inventories than voiceless stops. In contrast to findings of previous reports suggesting place of articulation differences, a somewhat comparable percentage of children in this study produced voiced bilabial, alveolar, and velar stops.
The mechanisms underlying the acquisition of speech-production ability in human infancy are not well understood. We tracked 4–12-mo-old English-learning infants’ and adults’ eye gaze while they ...watched and listened to a female reciting a monologue either in their native (English) or nonnative (Spanish) language. We found that infants shifted their attention from the eyes to the mouth between 4 and 8 mo of age regardless of language and then began a shift back to the eyes at 12 mo in response to native but not nonnative speech. We posit that the first shift enables infants to gain access to redundant audiovisual speech cues that enable them to learn their native speech forms and that the second shift reflects growing native-language expertise that frees them to shift attention to the eyes to gain access to social cues. On this account, 12-mo-old infants do not shift attention to the eyes when exposed to nonnative speech because increasing native-language expertise and perceptual narrowing make it more difficult to process nonnative speech and require them to continue to access redundant audiovisual cues. Overall, the current findings demonstrate that the development of speech production capacity relies on changes in selective audiovisual attention and that this depends critically on early experience.
This investigation looks at how third-graders are developing their speech in primary schools. The study identifies problems like limited vocabulary and emotional expressiveness, language being ...impacted by the coarsening of society standards, and inadequate parent-child communication. In order to tackle the observed underdevelopment, a comprehensive strategy has been proposed. It is stressed how important it is to have a step-by-step, all-encompassing educational plan that incorporates fun word games. The study presents a method for fostering expressiveness via folklore and creative writing, which fosters the best possible environment for language assimilation
•Mothers imitate their infants less than 10 % of the time.•Mothers are more likely to imitate speechlike vocalizations than non-speechlike vocalizations.•Most of the imitations that the infant hears ...are of non-speechlike vocalizations however.•Mothers respond to most of her infant’s vocalizations with a broad range of contingent and noncontingent responses.•Imitation does not appear to be a primary mechanism for promoting the transition from precanonical to canonical (speechlike) babble.
The aim of the present mixed cross-sectional and longitudinal study was to observe and describe some aspects of vocal imitation in natural mother-infant interaction. Specifically, maternal imitation of infant utterances was observed in relation to the imitative modeling, mirrored equivalence, and social guided learning models of infant speech development. Nine mother-infant dyads were audio-video recorded. Infants were recruited at different ages between 6 and 11 months and followed for 3 months, providing a quasi-longitudinal series of data from 6 through 14 months of age. It was observed that maternal imitation was more frequent than infant imitation even though vocal imitation was a rare maternal response. Importantly, mothers used a range of contingent and noncontingent vocal responses in interaction with their infants. Mothers responded to three-quarters of their infant's vocalizations, including speech-like and less mature vocalization types. The infants’ phonetic repertoire expanded with age. Overall, the findings are most consistent with the social guided learning approach. Infants rarely imitated their mothers, suggests a creative self-motivated learning mechanism that requires further investigation.
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