Leader-follower dynamics during early social interactions matter for infant word learning.

We know little about the mechanisms through which leader-follower dynamics during dyadic play shape infants' language acquisition. We hypothesized that infants' decisions to visually explore a specific object signal focal increases in endogenous attention, and that when caregivers respond to these proactive behaviors by naming the object it boosts infants' word learning. To examine this, we invited caregivers and their 14-mo-old infants to play with novel objects, before testing infants' retention of the novel object-label mappings. Meanwhile, their electroencephalograms were recorded. Results showed that infants' proactive looks toward an object during play associated with greater neural signatures of endogenous attention. Furthermore, when caregivers named objects during these episodes, infants showed greater word learning, but only when caregivers also joined their focus of attention. Our findings support the idea that infants' proactive visual explorations guide their acquisition of a lexicon.

A developmental model of audio-visual attention (MAVA) for bimodal language learning in infants and robots.

A social individual needs to effectively manage the amount of complex information in his or her environment relative to his or her own purpose to obtain relevant information. This paper presents a neural architecture aiming to reproduce attention mechanisms (alerting/orienting/selecting) that are efficient in humans during audiovisual tasks in robots. We evaluated the system based on its ability to identify relevant sources of information on faces of subjects emitting vowels. We propose a developmental model of audio-visual attention (MAVA) combining Hebbian learning and a competition between saliency maps based on visual movement and audio energy. MAVA effectively combines bottom-up and top-down information to orient the system toward pertinent areas. The system has several advantages, including online and autonomous learning abilities, low computation time and robustness to environmental noise. MAVA outperforms other artificial models for detecting speech sources under various noise conditions.

Dogs with a vocabulary of object labels retain them for at least 2 years.

Long-term memory of words has a crucial role in the developing abilities of young children to acquire language. In dogs, the ability to learn object labels is present in only a small group of uniquely gifted word learner (GWL) dogs. As they are very rare, little is known about the mechanisms through which they acquire such large vocabularies. In the current study, we tested the ability of five GWL dogs to retrieve 12 labelled objects 2 years after the object-label mapping acquisition. The dogs proved to remember the labels of between three and nine objects. The results shed light on the process by which GWL dogs acquire an exceptionally large vocabulary of object names. As memory plays a crucial role in language development, these dogs provide a unique opportunity to study label retention in a non-linguistic species.

Differences in the type of vocabulary understood by deaf and hearing students: Results to guide interventions.

INTRODUCTION: Vocabulary knowledge is an essential element in language development. There is evidence of significant differences in vocabulary knowledge between deaf children and hearing peers of the same age. These differences put deaf students at a disadvantage when compared to their hearing counterparts. The aim of this study was to investigate whether certain types of words characterise the lexical difficulties of deaf students. Our starting point is that this knowledge is needed to design interventions that are adapted to the particular needs of these students for their lexical development. METHODS: We evaluated the lexical comprehension of 90 Spanish students. The sample comprised 45 hearing students and 45 students with severe or profound hearing loss. Both groups were attending the later years of primary school (8 to -12-year-olds). They were tested using the Spanish Peabody Picture Vocabulary Test-III. The performance of both groups was statistically compared using percentiles and standard scores as well as a selected set of words from the test. RESULTS: No significant differences between hearing and deaf groups were found by age, sex, and sociocultural level. Significant differences were found between groups in their percentile and standard scores. There were no significant differences in performance between the two groups on only five of the 25 words with the highest error rate in the deaf group. The qualitative analysis of the remaining 20 words that were especially challenging for deaf students reveals results of interest which could help guide interventions. CONCLUSIONS: The results indicate the need for lexical intervention for deaf students in the final years of primary school. The specialised support service for deaf learners should approach the intervention by targeting a specific type of vocabulary, making the semantic relationships between these words more transparent and promoting a deeper understanding of them.

Associating neuromotor outcomes at 12 months with wearable sensor measures collected during early infancy in rural Guatemala.

BACKGROUND: Sensitive measures to predict neuromotor outcomes from data collected early in infancy are lacking. Measures derived from the recordings of infant movement using wearable sensors may be a useful new technique. METHODS: We collected full-day leg movement of 41 infants in rural Guatemala across 3 visits between birth and 6 months of age using wearable sensors. Average leg movement rate and fuzzy entropy, a measure to describe the complexity of signals, of the leg movements' peak acceleration time series and the time series itself were derived. We tested the three measures for the predictability of infants' developmental outcome, Bayley Scales of Infant and Toddler Development III motor, language, or cognitive composite score assessed at 12 months of age. We performed quantile regressions with clustered standard errors, accounting for the multiple visits for each infant. RESULTS: Fuzzy entropy was associated with the motor composite score at the 0.5 quantiles; this association was not found for the other two measures. Also, no leg movement characteristic was associated with language or cognitive composite scores. CONCLUSION: We propose that the entropy of leg movement associated peak accelerations calculated from the wearable sensor data collected for a full-day can be considered as one predictor for infants' motor developmental outcome assessed with Bayley Scales of Infant and Toddler Development III at 12 months of age.

Validation of Serbian version of the LittlEARS® Early Speech Production Questionnaire for the assessment of early language development in typically developing children.

OBJECTIVE: The LittlEARS® Early Speech Production Questionnaire (LEESPQ) was developed to provide professionals with valuable information about children's earliest language development and has been successfully validated in several languages. This study aimed to validate the Serbian version of the LEESPQ in typically developing children and compare the results with validation studies in other languages. METHODS: The English version of the LEESPQ was back-translated into Serbian. Parents completed the questionnaire in paper or electronic form either during the visit to the paediatric clinic or through personal contact. A total of 206 completed questionnaires were collected. Standardized expected values were calculated using a second-order polynomial model for children up to 18 months of age to create a norm curve for the Serbian language. The results were then used to determine confidence intervals, with the lower limit being the critical limit for typical speech-language development. Finally, the results were compared with German and Canadian English developmental norms. RESULTS: The Serbian LEESPQ version showed high homogeneity (r = .622) and internal consistency (α = .882), indicating that it almost exclusively measures speech production ability. No significant difference in total score was found between male and female infants (U = 4429.500, p = .090), so it can be considered a gender-independent questionnaire. The results of the comparison between Serbian and German (U = 645.500, p = .673) and Serbian and English norm curves (U = 652.000, p = .725) show that the LEESPQ can be applied to different population groups, regardless of linguistic, cultural or sociological differences. CONCLUSION: The LEESPQ is a valid, age-dependent and gender-independent questionnaire suitable for assessing early speech development in children aged from birth to 18 months.

Decomposing modal thought.

Cognitive scientists have become increasingly interested in understanding how natural minds represent and reason about possible ways the world could be. However, there is currently little agreement on how to understand this remarkable capacity for modal thought. We argue that the capacity for modal thought is built from a set of relatively simple component parts, centrally involving an ability to consider possible extensions of a part of the actual world. Natural minds can productively combine this ability with a range of other capacities, eventually allowing for the observed suite of increasingly more sophisticated ways of modal reasoning. We demonstrate how our (de)compositional account is supported by both the trajectory of children's developing capacity for reasoning about possible ways the world could be and by what we know about how such modal thought is expressed within and across natural languages. Our approach makes new predictions about which kinds of capacities are required by which kinds of experimental tasks and, as a result, contributes to settling currently open theoretical questions about the development of modal thought and the acquisition of modal vocabulary in children. Our work also provides a more systematic way of understanding possible variation in modal thought and talk, and, more generally, paves the way toward a unified theory that will ultimately allow researchers across disciplines to relate their findings to each other within a framework of shared assumptions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

[A normative study of speech development in Mandarin-speaking infants and children].

Objective: The aim of this study is to analyze the development of speech ability in Mandarin-speaking infants and children with normal hearing using MUSS and to provide a normal value control for the evaluation of speech ability in children with hearing loss. Methods: From September 2012 to January 2023, a total of 256 infants and children aged 1-60 months in Mandarin language environment participated in this study. 200 infants and children aged from 1 to 60 months were finally included, whose hearing was considered normal according to the history collection, high-risk registers for hearing loss and hearing screening. All infants and children were divided into 10 groups with 20 infants or children in each group. They were: 1 month, 2-3 months, 4-6 months, 7-9 months, 10-12 months, 13-18 months, 19-24 months, 25-36 months, 37-48 months, and 49-60 months. Using SPSS 19.0 software for data analysis, we calculated regression equations based on fitting curves. Results: The language ability of infants and children with normal hearing increased with age and reached ceiling at 56.5months.The regression equation was: score=-0.009 3×(age) 2+2.179×(age)+6.718 6, r2=0.85; age=0.003 9×(score) 2+0.148 4×(score)+2.708, r2=0.85. Conclusions: The speech ability of infants and children with normal hearing shows an increasing trend with age. Scores of different speech skills can be predicted according to their age. Age can also be predicted according to their scores of different speech skills.

[Early vocabulary development in Mandarin children with cochlear implantation].

Objective: To investigate the development of receptive and expressive vocabulary in Mandarin-speaking children with cochlear implants (CI) during the first year after CI activation. Methods: A total of 827 children (411 boys and 416 girls) who were implanted CI before 2.5 years of age from October 2019 to December 2022 in the Department of Auditory Implantation, Shandong Provincial ENT Hospital were included in this study. The Infant Checklist of the Mandarin Early Vocabulary Inventory (EVI) was used to assess the quantity and content of receptive and expressive vocabulary at the time of CI activation and at the 1st, 3rd, 6th, 9th, 12th months post-activation. SPSS 22.0 was used to describe the receptive and expressive vocabulary of CI children at the first year after activation. Results: During the first year after CI activation, CI children's receptive and expressive vocabulary consistently increased with the CI usage. The average number of receptive vocabulary and expressive vocabulary respectively increased from 0 to 178, and from 0 to 97. At the first year of post-activation, the number of receptive and expressive vocabulary of CI children were superior to that of hearing-age matched typical-hearing children, but fell behind of that of chronological age matched typical-hearing children. In terms of lexical categories, receptive and expressive vocabulary was acquired in the following order: nouns, verbs, adjectives, and pronouns. Among the top 50 words that CI children could express, nouns were the most common, then followed by verbs, adjectives, and pronouns. Father's education level can significantly and positively predictethe receptive vocabulary of CI children at the first year post-activation. At the first year after CI activation, the 10th, 25th, 50th, 75th, and 90th percentiles were 113, 149, 178, 202, 223 for the receptive vocabulary, and 9, 37, 97, 148, 188 for expressive vocabulary. Conclusion: For Mandarin speaking children with CI, the receptive and expression vocabulary continuely increased within the first year after CI activation. The ability to grasp receptive vocabulary precedes the ability to express expressive vocabulary. Compared to hearing-age matched typical-hearing children, CI children showed faster rate of the vocabulary growth, and earlier and more frequently verb expression. However, it still larged behind that of chronological age matched hearing normal children. CI children respectively understood and expressed nouns and verbs the first. In children with CI, the first concepts understood and expressed were nouns and verbs. Among the first 50 words expressed, nouns were the most numerous, and the age at which verbs were acquired was earlier than that for hearing-age matched typical-hearing children.

Early, typical, and late talkers: an exploratory study on predictors of language development in the first two years of life.

Background: The consensus in scientific literature is that each child undergoes a unique linguistic development path, albeit with shared developmental stages. Some children excel or lag behind their peers in language skills. Consequently, a key challenge in language acquisition research is pinpointing factors influencing individual differences in language development. Methods: We observed children longitudinally from 3 to 24 months of life to explore early predictors of vocabulary size. Based on the productive vocabulary size of children at 24 months, 30 children met our sample selection criteria: 10 late talkers and 10 early talkers, and we compared them with 10 typical talkers. We evaluated interactive behaviors at 3, 6, 9 and 12 months, considering vocal production, gaze at mother's face, and gestural production during mother-child interactions, and we considered mothers' report of children's actions and gestures and receptive-vocabulary size at 15 and 18 months. Results: Results indicated early precursors of language outcome at 24 months identifiable as early as 3 months in vocal productions, 6 months for gaze at mother's face and 12 months for gestural productions. Conclusions: Our research highlights both theoretical and practical implications. Theoretically, identifying the early indicators of belonging to the group of late or early talkers underscores the significant role of this developmental period for future studies. On a practical note, our findings emphasize the crucial need for early investigations to identify predictors of vocabulary development before the typical age at which lexical delay is identified.

Lead contamination in human milk affects infants' language trajectory: results from a prospective cohort study.

Infants growing up in low- and middle-income countries are at increased risk of suffering adverse childhood experiences, including exposure to environmental pollution and lack of cognitive stimulation. In this study, we aimed to examine the levels of metals in the human milk of women living in São Paulo City, Brazil, and determine the effects on infants' neurodevelopment. For such, a total of 185 human milk samples were analyzed for arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) using inductively coupled plasma mass spectrometry (ICP-MS). We applied the Bayley scales of infant and toddler development Third Edition (Bayley-III) to assess developmental milestones. In our analysis, we found a mean (standard deviation) concentration of As in human milk equal to 2.76 (4.09) µg L-1, followed by Pb 2.09 (5.36) and Hg 1.96 (6.68). Cd was not detected. We observed that infants exposed to Pb presented language trajectories lower than non-exposed infants (ß = -0.413; 95% CI -0.653, -0.173) after adjustment for infant age, maternal education, socioeconomic status, infant sex, and sample weights. Our results report As, Pb, and Hg contamination in human milk, and that infant exposure to Pb decreased infants' language development. These results evidence maternal-child environmental exposure and its detrimental impact on infants' health.

Disentangling the roles of age and knowledge in early language acquisition: A fine-grained analysis of the vocabularies of infant and child language learners.

The words that children learn change over time in predictable ways. The first words that infants acquire are generally ones that are both frequent and highly imageable. Older infants also learn words that are more abstract and some that are less common. It is unclear whether this pattern is attributable to maturational factors (i.e., younger children lack sufficiently developed cognitive faculties needed to learn abstract words) or linguistic factors (i.e., younger children lack sufficient knowledge of their language to use grammatical or contextual cues needed to figure out the meaning of more abstract words). The present study explores this question by comparing vocabulary acquisition in 53 preschool-aged children (M = 51 months, range = 30-76 months) who were adopted from China and Eastern Europe after two and half years of age and 53 vocabulary-matched infant controls born and raised in English speaking families in North America (M = 24 months, range = 16-33 months). Vocabulary was assessed using the MB-CDI Words and Sentences form, word frequency was estimated from the CHILDES database, and imageability was measured using adult ratings of how easily words could be pictured mentally. Both groups were more likely to know words that were both highly frequent and imageable (resulting in an over-additive interaction). Knowledge of a word was also independently affected by the syntactic category that it belongs to. Adopted preschoolers' vocabulary was slightly less affected by imageability. These findings were replicated in a comparison with a larger sample of vocabulary-matched controls drawn from the MB-CDI norming study (M = 22 months, range = 16-30 months; 33 girls). These results suggest that the patterns of acquisition in children's early vocabulary are primarily driven by the accrual of linguistic knowledge, but that vocabulary may also be affected by differences in early life experiences or conceptual knowledge.

Does poor oral health impact on young children's development? A rapid review.

Background The extent to which poor oral health in young children impacts developmental milestones is unclear.Aim To review the evidence of association between poor oral health and development of young children (0-5 years).Method A rapid review was conducted. Medline was searched for articles in English published from 2000 onwards. The outcomes considered were the impact of poor oral health on speech and language development, oral health-related quality of life (OHRQoL), school performance and attendance.Results In total, 15 studies were included: four systematic reviews, a critical review and 10 primary studies. All data were from observational or cross-sectional studies. Premature extraction of primary maxillary incisors was associated with change in speech sounds and articulation. Two primary studies found associations between early childhood caries and physical and psychomotor deficiencies, while acknowledging a web of causation with other factors, including socioeconomic status. Children with dental caries reported lower OHRQoL. Studies found caries experience was associated with preschool absenteeism.Conclusion Poor oral health in young children appears to be associated with speech and language development, OHRQoL, and school attendance and performance. However, there are significant limitations in the existing evidence, with further high-quality, observational, longitudinal research required to fully understand the impact of poor oral health on the development of young children. Strategies to improve oral health by health and education professionals are needed to ensure young children reach their potential.

Auditory and Language Abilities in Children with Takenouchi-Kosaki Syndrome: A Systematic Review.

Takenouchi-Kosaki syndrome (TKS) is a rare congenital disease caused by a de novo mutation in the Cell Division Cycle 42 (CDC42) gene. Patients with TKS present facial and body dysmorphisms, hematologic and immune dysregulation, intellectual disability, neurodevelopmental delay and hearing loss. The aim of this study is to review the literature, focusing on hearing and language abilities in children with TKS. A systematic search on PubMed, Scopus and Web of Science databases was performed, including twelve studies for a total of 13 patients. Hearing loss (HL) occurs in a great percentage of patients (84.6%); nonetheless, auditory threshold, severity of HL and language abilities were reported in a few cases. In two studies, auditory rehabilitation strategies were described. Although several studies have investigated the hematological features of TKS, still only a few authors have focused on the audiological and language abilities of these children. Given the fact that HL has a significant impact on behaviors, communications skills, and quality of life, it is important to adequately assess and rehabilitate patients early with this syndrome. Further studies are needed to improve the knowledge about this topic and improve the quality of life of patients with TKS.

Language development in children from a public cochlear implant program.

OBJECTIVE: To evaluate the rate of loss to follow-up in a cochlear implant program from the public health system in Southern Brazil as well as the characteristics of hearing loss, sociodemographic, sociocultural and the development of oral language in children with prelingual deafness. METHODS: Retrospective cohort study with children who underwent CI surgery between 2010 and 2020. Data was collected through of interviews and review of medical records. The language development assessment was performed using the MUSS, MAIS and IT-MAIS scales. For the classification of language development, we used as parameters the values (mean ±â€¯SD) found in a previous national study. From those values, the Z-score for each patient at each hearing age (time of experience with the cochlear implant) was calculated. RESULTS: Of the 225 children implanted between 2010-2020, 129 were included in this study. The rate of loss to follow-up in the program was 42.6%. The mean age at first surgery was 40.5 (±16.9) months, with 77.5% of patients having received a unilateral implant. Language results below the expected for hearing age (

Statistical learning ability at 17 months relates to early reading skills via oral language.

Statistical learning ability has been found to relate to children's reading skills. Yet, statistical learning is also known to be vital for developing oral language skills, and oral language and reading skills relate strongly. These connections raise the question of whether statistical learning ability affects reading via oral language or directly. Statistical learning is multifaceted, and so different aspects of statistical learning might influence oral language and reading skills distinctly. In a longitudinal study, we determined how two aspects of statistical learning from an artificial language tested on 70 17-month-old infants-segmenting sequences from speech and generalizing the sequence structure-related to oral language skills measured at 54 months and reading skills measured at approximately 75 months. Statistical learning segmentation did not relate significantly to oral language or reading, whereas statistical learning generalization related to oral language, but only indirectly related to reading. Our results showed that children's early statistical learning ability was associated with learning to read via the children's oral language skills.

Is That You I Hear? Speaker Familiarity Modulates Neural Signatures of Lexical-semantic Activation in 18-month-old Infants.

Developmental language studies have shown that lexical-semantic organization develops between 18 and 24 months of age in monolingual infants. In the present study, we aimed to examine whether voice familiarity facilitates lexical-semantic activation in the infant brain. We recorded the brain activity of 18-month-old, French-learning infants using EEG while they listened to taxonomically related and unrelated spoken word pairs by one voice with which they were familiarized with before the experiment, and one voice with which they were not familiarized. The ERPs were measured in response to related and unrelated target words. Our results showed an N400 effect (greater amplitudes for unrelated as opposed to related target words) over the left hemisphere, only for the familiar voice, suggesting that the voice familiarity facilitated lexical-semantic activation. For unfamiliar voices, we observed an earlier congruence effect (greater amplitudes for related than for unrelated target words). This suggests that although 18-month-olds process lexical-semantic information from unfamiliar speakers, their neural signatures of lexical-semantic processing are less mature. Our results show that even in the absence of personal relation with a speaker, familiarity with a voice augments infant lexical-semantic processing. This supports the idea that extralinguistic information plays a role in infant lexical-semantic activation.

Early-emerging combinatorial thought: Human infants flexibly combine kind and quantity concepts.

Combinatorial thought, or the ability to combine a finite set of concepts into a myriad of complex ideas and knowledge structures, is the key to the productivity of the human mind and underlies communication, science, technology, and art. Despite the importance of combinatorial thought for human cognition and culture, its developmental origins remain unknown. To address this, we tested whether 12-mo-old infants (N = 60), who cannot yet speak and only understand a handful of words, can combine quantity and kind concepts activated by verbal input. We proceeded in two steps: first, we taught infants two novel labels denoting quantity (e.g., "mize" for 1 item; "padu" for 2 items, Experiment 1). Then, we assessed whether they could combine quantity and kind concepts upon hearing complex expressions comprising their labels (e.g., "padu duck", Experiments 2-3). At test, infants viewed four different sets of objects (e.g., 1 duck, 2 ducks, 1 ball, 2 balls) while being presented with the target phrase (e.g., "padu duck") naming one of them (e.g., 2 ducks). They successfully retrieved and combined on-line the labeled concepts, as evidenced by increased looking to the named sets but not to distractor sets. Our results suggest that combinatorial processes for building complex representations are available by the end of the first year of life. The infant mind seems geared to integrate concepts in novel productive ways. This ability may be a precondition for deciphering the ambient language(s) and building abstract models of experience that enable fast and flexible learning.

The Contribution of Noun and Verb Lexicon Sizes to Later Grammatical Outcomes in Mandarin-Speaking Children With Cochlear Implants.

PURPOSE: The present study evaluated the applicability of the sentence-focused framework to Mandarin-speaking children with cochlear implants (CIs) by examining the relative contribution of receptive/expressive noun and verb lexicon sizes to later grammatical complexity. METHOD: Participants were 51 Mandarin-speaking children who received cochlear implantation before 30 months of age. At 12 months after CI activation, parents were asked to endorse words that their child could understand only or understand and say using the infant version of the Early Vocabulary Inventory. At 24 months after CI activation, parents were asked to endorse the grammatical structures that their children were able to say using the Grammatical Complexity subtest in the Mandarin Communicative Development Inventory-Taiwan. Children's receptive/expressive noun and verb lexicon sizes and grammatical complexity scores were computed from these parent checklists. RESULTS: Correlational analyses showed that children's receptive/expressive noun and verb lexicon sizes at 12 months after CI activation were all highly correlated with their grammatical complexity scores at 24 months after CI activation (ρs = .52-.63, ps < .001). Regression analyses further revealed that verb lexicon sizes at 12 months after CI activation outweighed noun lexicon sizes in accounting for grammatical complexity at 24 months after CI activation. CONCLUSIONS: Our findings supported the prediction of the sentence-focused framework. Emphasizing the role of verbs in early intervention has the potential to enhance grammatical outcomes in Mandarin-speaking children with CIs. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.26129044.

The Development of Gesture Skills in Chinese Autistic Children: The Predictive Roles of Age and Language Ability.

PURPOSE: Gesture delay in autistic infants and toddlers has been widely reported. The developmental trajectory of gesture production during early childhood is understudied. Thus, little is known about the possible changes of gesture production over time. The present study aimed to document the development of gesture production in autistic children and examine whether child-based factors (chronological age and initial language skills) predicted gesture development. METHOD: A total of 33 Chinese-speaking autistic children (Mage = 56.39 months, SD = 8.54 months) played with their parents at four time points over a 9-month period. Their speech was transcribed, and their gestures were coded from parent-child interaction. Multilevel modeling analysis was used to investigate the development of gesture and its associated factors. RESULTS: The total number of gestures produced by autistic children decreased over time. Among different factors, children's initial age significantly and negatively predicted children's gesture production, while initial language positively predicted children's gesture production. CONCLUSIONS: Gesture delay persists in preschool age. The decline in gesture production was associated with children's age and initial language ability. These findings shed light on the difficulties surrounding gesture use in autistic children.