Exploring word-referent mapping in Mandarin-speaking late-talkers at 33 months and its language predictors at 27 months: An eye-tracking study.

BACKGROUND AND AIMS: This longitudinal study investigated the language skills, phonological working memory and lexical-tone perception of Mandarin-speaking late-talkers (LTs) and those with typical language development (TLD) at 27 months, while also examining their connections with novel word-referent mapping (W-R mapping) through eye-tracking at 33 months. METHODS AND PROCEDURES: Participants included 22 Mandarin-speaking 27-month-old LTs and 22 toddlers with TLD. Data on expressive and receptive language abilities, as well as phonological working memory and lexical-tone perception, were collected when participants were 27 months old. An eye-tracking paradigm was further employed during the word-learning tasks, which included W-R mapping and word-identification test (W-I test) phases at 33 months. Multilevel models were used to analyse participants' gaze pattern trajectories. OUTCOMES AND RESULTS: At 27 months, LT toddlers exhibited poorer language skills (receptive: p = 0.015, expressive: p < 0.001), lexical-tone perception (p < 0.001) and phonological working memory (p < 0.001) compared to those with TLD, even after considering maternal educational level and participants' fine motor ability. During the W-I test phase, we observed that LT toddlers showed a slower increase in fixations on the novel target image while listening to the corresponding novel word over time, compared to TLD toddlers (linear: p = 0.011, quadratic: p = 0.007) after adding confounders. Further, expressive language ability at 27 months old was a predictor of their newly established W-R mappings at 33 months old (p = 0.016). Additionally, the toddler's phonological working memory and lexical-tone perception were associated with their expressive language ability (p = 0.001 and < 0.001). CONCLUSIONS AND IMPLICATIONS: These findings indicate that the novel W-R mapping is not as robust in LTs as in TLDs, and the skills necessary for word learning share similarities with a wide range of expressive language abilities. Moreover, poor expressive language abilities were associated with deficits in lexical processing abilities; that is, phonological working memory and lexical-tone perception. These findings suggest the need for interventions aimed at improving LTs' lexical processing abilities to strengthen their lagging word-learning skills at toddlerhood. WHAT THIS PAPER ADDS: What is already known on this subject Late-talkers (LTs) exhibit delays in expressive vocabulary development. Furthermore, they also perform poorly in word learning. What this paper adds to existing knowledge The eye-tracking paradigm was employed and found that novel word-referent mapping (W-R mapping) is not as robust in LTs as in those with typical language development. Toddlers' early expressive language ability could predict their ability to establish novel W-R mappings. Furthermore, the better the phonological working memory and lexical-tone perception of LTs are, the better their early expressive language ability is. What are the clinical implications of this work? Interventions might consider incorporating strategies to improve phonological working memory and lexical-tone perception to help Mandarin-speaking LTs enhance linguistic capacities and build robust novel W-R mapping.

The timescales of word learning in children with language delays: In-the-moment mapping, retention, and generalization.

Learning new words and, subsequently, a lexicon, is a time-extended process requiring encoding of word-referent pairs, retention of that information, and generalization to other exemplars of the category. Some children, however, fail in one or more of these processes resulting in language delays. The present study examines the abilities of children who vary in vocabulary size (including both children with normal language (NL) and late talking (LT) children) across multiple timescales/processes - known and novel word mapping, novel word retention, and novel noun generalization. Results indicate that children with lower language skills suffer from deficits in quick in-the-moment mapping of known words compared to their NL peers, but age and vocabulary size rather than normative vocabulary ranking or NL/LT status better predicts performance on retention and generalization processes. Implications for understanding language development as a holistic process with multiple interacting variables are discussed.

Receptive and expressive language ability differentially support symbolic understanding over time: Picture comprehension in late talking and typically developing children.

Symbols are a hallmark of human communication, and a key question is how children's emerging language skills relate to their ability to comprehend symbols. In particular, receptive and expressive vocabulary may have related, but distinct, roles across early development. In a longitudinal study of late talking (LT) and typically developing (TD) children, we differentiated the extent to which expressive and receptive language skills predicted symbolic understanding as reflected in picture comprehension and how language skills inter-related with social skills. LT and TD children were tested on a picture comprehension task that manipulated the availability of verbal labels at 2.0-2.4 years and 3.5-3.9 years of age. Although all children improved in accuracy over time as expected, TD children exhibited an advantage over LT children, despite both groups using verbal labels to inform their mapping of picture-object relationships. Receptive and expressive vocabulary also differed in their contribution at different ages; receptive vocabulary predicted performance at ∼2.0 years of age, and expressive vocabulary predicted performance at ∼3.5 years of age. Task performance at 3.5 years was predicted by earlier receptive vocabulary, but this effect was largely mediated by concurrent expressive vocabulary. Social ability across the whole sample at ∼2.0 years also predicted and mediated the effect of receptive vocabulary on concurrent task performance. These findings suggest that LT children may have delays in developing picture comprehension over time and also that social ability and language skills may differentially relate to symbolic understanding at key moments across development.

School-entry language outcomes in late talkers with and without a family risk of dyslexia.

Children with familial risk (FR) of dyslexia and children with early language delay are known to be at risk for later language and literacy difficulties. However, research addressing long-term outcomes in children with both risk factors is scarce. This study tracked FR and No-FR children identified as late talkers at 2 years of age and reports development from 4;6 through 6 years. We examined the possible effects of FR-status and late talking (LT) status, respectively, on language skills at school entry, and whether FR-status moderated the associations between 4;6-year and 6-year language scores. Results indicated an effect of LT status on language at both ages, while FR status affected language skills at 6 years only. The interaction between LT and FR statuses was not significant, implying that LT status affected language skills independently of the child's FR status. A proportion of late talkers developed typical language at 6 years of age, while some FR children with typical vocabulary skills in toddlerhood had emerging developmental language disorder by school entry. FR status had a moderating effect on the association between expressive grammar at ages 4;6 and 6 years. Possible explanations for the effect of FR status on language skills are discussed. We highlight limitations in the study size and suggest how these preliminary findings can inform future research.

Measures of Early Social Communication and Vocabulary Production to Predict Language Outcomes at Two and Three Years in Late-Talking Toddlers.

BACKGROUND: Late talkers are a heterogeneous group of toddlers and reliable predictors of persistent language delay have been elusive. The purpose of this study was to determine the extent to which early social communication and vocabulary production predicted variance in language outcomes at 2 and 3 years of age. METHODS: Participants were 408 typically developing and late-talking toddlers who completed the Communication and Symbolic Behavior Scales Caregiver Questionnaire and Behavior Sample (CSBS CQ and CSBS BS) at a mean of 20 months, the Language Development Survey (LDS) at a mean of 24 months, and the Mullen Scales of Early Learning (MSEL) at a mean of 25 months. A subgroup of 198 children completed a second MSEL at 3 years of age. Associations among the LDS, CSBS CQ, CSBS BS, and MSEL were examined using correlational and hierarchical linear regression analyses. Logistic regression was used to examine each measure's contribution to predicting language delay at 2 and 3 years. RESULTS: Moderate to large correlations were observed among all variables. The LDS, CSBS CQ, and CSBS BS added unique contributions to the prediction of 2- and 3-year expressive and receptive language outcomes. Measures of speech and vocabulary production were the strongest predictors of language outcomes at age 2. At age 3, social and symbolic communication played a more significant role in accounting for variance in expressive and receptive language outcome. A similar pattern emerged for the categorical prediction of language delay. CONCLUSIONS: Measures of social communication between 18-21 months added important information to predicting language outcomes at 2 and 3 years, above and beyond parent-reported expressive vocabulary production measured at 24 months, with small effect sizes overall. Implications for identifying younger children who are at risk for continued language delay and recommendations for referral to early intervention programs are discussed.

The syntactic and semantic features of two-year-olds' verb vocabularies: a comparison of typically developing children and late talkers.

Children with language disorders have particular difficulty with verbs, but when this difficulty emerges is unknown. We examined syntactic (transitive, intransitive, ditransitive) and semantic (manner, result) features of two-year-olds' verb vocabularies, contrasting late talkers and typically developing children to look for early differences in verb vocabulary. We conducted a retrospective analysis of parent-reported expressive vocabulary from the Language Development Survey (N = 564, N(LT) = 62) (Rescorla, 1989). Verbs were coded for the presence or absence of each syntactic and semantic feature. Binomial mixed-effects regressions revealed the effect of feature on children's knowledge and whether feature interacted with group classification. Our results revealed mostly similarities between late talkers and typically developing children. All children's vocabularies showed a bias against verbs that occur in ditransitive frames. One feature showed a difference between groups: late talkers showed a bias against manner verbs that typically developing children did not.

The Monosyllable Imitation Test for Toddlers: influence of stimulus characteristics on imitation, compliance and diagnostic accuracy.

BACKGROUND: Although verbal imitation can provide a valuable window into the developing language abilities of toddlers, some toddlers find verbal imitation challenging and will not comply with tests that involve elicited verbal imitation. The characteristics of stimuli that are offered to toddlers for imitation may influence how easy or hard it is for them to imitate. This study presents a new test of elicited imitation-the Monosyllable Imitation Test for Toddlers (MITT)-comprising stimuli of varying characteristics and test features designed to optimize compliance. AIMS: To investigate whether the stimulus characteristics of neighbourhood density and consonant complexity have independent and/or convergent influences on imitation accuracy; and to examine non-compliance rates and diagnostic accuracy of the MITT and an existing test, the Test of Early Nonword Repetition (TENR) (Stokes and Klee 2009a). METHODS & PROCEDURES: Fifty-two toddlers (25-35 months) participated. Twenty-six had typically developing language (TDs) and 26 were defined as late talkers (LTs) based on parent-reported vocabulary. The MITT stimuli were created by manipulating both neighbourhood density (dense or sparse) and consonant complexity (early- or late-developing initial consonant). The MITT was designed to maximize compliance by: (1) using eight monosyllabic stimuli, (2) providing three exposures to stimuli and (3) embedding imitation in a motivating context: a computer animation with reasons for imitation. OUTCOMES & RESULTS: Stimulus characteristics influenced imitation accuracy in TDs and LTs. For TDs, neighbourhood density had an independent influence, whereas for LTs consonant complexity had an independent influence. These characteristics also had convergent influences. For TDs, stimuli were all equally easy to imitate, except those that were both sparse and contained a late-developing consonant which were harder to imitate. For LTs, stimuli that were both dense and contained an early-developing consonant were easier to imitate than any other stimuli. Two LTs and no TDs were non-compliant with the MITT. With the TENR, five LTs and two TDs were non-compliant. The MITT and TENR yielded similar levels of diagnostic sensitivity, but the TENR offered higher specificity rates. Subsets of stimuli from the MITT and the TENR also showed diagnostic promise when explored post-hoc. CONCLUSIONS & IMPLICATIONS: Stimulus characteristics converge to influence imitation accuracy in both TD and LT toddlers and therefore should be considered when designing stimuli. The MITT resulted in better compliance than the TENR, but the TENR offered higher specificity. Insights about late talking, elicited imitation and speech production capabilities are discussed.

Replication of a single-case design cross-situational statistically based word learning treatment for late talking children.

PURPOSE: Late talking children are at risk of ongoing language impairment. This intervention study replicated and extended research based on cross-situational statistical learning principles. METHOD: Three late talking children (age 24-32 months) were enrolled into the concurrent multiple baseline single-case experimental intervention study. The intervention consisted of 16 sessions over eight/nine weeks, including 10-11 pairs of target and control words (three per session). Children heard the target words a minimum of 64 times per session, in sentences with high linguistic variability in varied play activities. RESULT: All children increased production of target words and expressive vocabulary, with statistically significant differences between word acquisition in baseline and intervention phases. One of the three children learnt statistically significantly more target words than control words. CONCLUSION: The results replicated the findings of previous research for some but not all of the participants, providing individual evidence that this approach has promise as a therapy technique for late talking children.

[Early indicators of childhood apraxia of speech in late talkers: general guidelines to intervention]. / Indicadores tempranos de dispraxia verbal en el inicio tardío: orientaciones para la intervención Inmaculada.

INTRODUCTION: The population of children with slow emergence of language development varies widely, both in their initial profile and in their response to intervention. In this sense, there is a group of late talkers who continue to show persistent language difficulties, in some cases exhibiting signs compatible with verbal dyspraxia. METHOD: In this paper we present the different response to intervention of two profiles of late talkers. Specifically, the Target Word© program (Hanen Centre) was implemented, which is addressed to latetalking children and their families. It combines the technique of focused stimulation with guidance to parents on strategies that stimulate global language development. RESULTS: Much of the symptomatology shown in one case of poor progress coincides with retrospective descriptions of children subsequently diagnosed with dyspraxia and can be considered early indicators of the disorder: unintelligibility, reduced consonant inventory or difficulties in word repetition. DISCUSSION: The different response to intervention contributes to diagnostic decision making and the early implementation of specific strategies directed to improve speech learning skills by incorporating motor learning principles. The few studies of intervention in suspected verbal dyspraxia in early childhood offer promising results on a variety of speech assessment indicators, and provide practitioners with valuable information with which to support the intervention in this population.

Introducción: La población de niños que comienzan con lentitud el desarrollo del lenguaje varía ampliamente, tanto en su perfil inicial como en la respuesta a la intervención. En este sentido, existe un grupo de niños, denominados hablantes tardíos, que continúan mostrando dificultades persistentes en el lenguaje. Algunos de estos niños muestran signos compatibles con la dispraxia verbal, y que se ponen de manifiesto a lo largo de la intervención. Método: En este trabajo presentamos la diferente respuesta a la intervención de dos perfiles de hablante tardío. Concretamente, se aplicó el programa Target Word©, del centro Hanen, que conjuga la técnica de la estimulación focalizada con la orientación a padres sobre estrategias que promueven el desarrollo del lenguaje. Resultados: Gran parte de la sintomatología mostrada en uno de los dos casos, que experimentó un progreso pobre, coincide con las descripciones retrospectivas de niños posteriormente diagnosticados con dispraxia y pueden considerarse indicadores tempranos del trastorno: ininteligibilidad, inventario consonántico reducido o dificultades en la repetición de palabras. Discusión: La diferente respuesta a la intervención contribuye a la toma de decisiones diagnósticas y a la aplicación temprana de estrategias específicas para la mejora de las habilidades de aprendizaje del habla mediante la incorporación de los principios del aprendizaje motor. Los escasos estudios de intervención en casos de sospecha de dispraxia verbal en la infancia temprana ofrecen resultados prometedores en diversos indicadores de evaluación del habla, y proporcionan a los profesionales una información valiosa en la que fundamentar la intervención en esta población.

Parent implementation of a treatment for late talkers based on cross-situational statistical learning principles: Treatment fidelity and acceptability.

PURPOSE: Early intervention based on principles of cross-situational statistical learning (CSSL) for late-talking children has shown promise. This study explored whether parents could be trained to deliver this intervention protocol with fidelity and if they found the intervention to be acceptable. METHOD: Mothers of four English-speaking children aged 18-30 months who scored <10th centile for expressive vocabulary were recruited to an 8-week group training program. Parents were taught principles of CSSL and asked to perform 16 home treatment sessions (30 minutes each) in total, providing auditory bombardment of target words in full sentences at high dose number and syntactic variability, using a range of physical exemplars. Home diaries and two videotaped sessions measured treatment fidelity. Pre- and post-treatment questionnaires measured acceptability. RESULT: One parent discontinued the study after the second group training session. Three parents completed 15/16 group training sessions and reported completing 87% of home sessions. Two parents demonstrated implementing the intervention as per the target dose number by the first fidelity session (Weeks 2/3), and the third parent was very close to meeting target dose number by the second fidelity session (Weeks 7/8). CONCLUSION: Parents can be trained to deliver an intervention based on cross-situational statistical learning principles.

Lexical skills and gesture use: A comparison between expressive and receptive/expressive late talkers.

BACKGROUND: Studies on late talkers (LTs) highlighted their heterogeneity and the relevance of describing different communicative profiles. AIMS: To examine lexical skills and gesture use in expressive (E-LTs) vs. receptive-expressive (R/E-LTs) LTs through a structured task. METHODS AND PROCEDURES: Forty-six 30-month-old screened LTs were distinguished into E-LTs (n= 35) and R/E-LTs (n= 11) according to their receptive skills. Lexical skills and gesture use were assessed with a Picture Naming Game by coding answer accuracy (correct, incorrect, no response), modality of expression (spoken, spoken-gestural, gestural), type of gestures (deictic, representational), and spoken-gestural answers' semantic relationship (complementary, equivalent, supplementary). OUTCOMES AND RESULTS: R/E-LTs showed lower scores than E-LTs for noun and predicate comprehension with fewer correct answers, and production with fewer correct and incorrect answers, and more no responses. R/E-LTs also exhibited lower scores in spoken answers, representational gestures, and equivalent spoken-gestural answers for noun production and in all spoken and gestural answers for predicate production. CONCLUSIONS AND IMPLICATIONS: Findings highlighted more impaired receptive and expressive lexical skills and lower gesture use in R/E-LTs compared to E-LTs, underlying the relevance of assessing both lexical and gestural skills through a structured task, besides parental questionnaires and developmental scales, to describe LTs' communicative profiles.

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.

Lexical development in Kuwaiti Arabic in typically developing children and late talkers.

INTRODUCTION: This study explored vocabulary development and lexical composition in young typically developing (TD) Kuwaiti children and late talkers (LT) using the Kuwaiti Arabic Communicative Development Inventory-Words and Sentences (KACDI-WS) Abdalla et al., 2016). The sample included 161 children aged 20 to 37 months: 127 TD and 34 children who were late talkers (LT group). The late talkers were first identified based on a background questionnaire answered by the parents. All the caregivers completed a 698-item web-based KACDI expressive vocabulary inventory by selecting non-imitative words that their children produced. RESULTS: Lexical size and composition (nouns, predicates, and closed-class words) were analyzed. Across the TD age groups (20-26, 27-31, 32-37 months), a significant age effect for vocabulary size and composition was found in favor of the older groups. Nouns were more prevalent than predicates or closed-class words in within-group comparisons. The vocabulary size of the TD (M= 263.8) was significantly larger than that of the LT group (M= 69.2). The development of their lexical composition followed a similar pattern. CONCLUSIONS: The results suggested that the KACDI parent report instrument has the potential for measuring vocabulary development in TD children and could serve as an initial screening tool to identify late talkers.

Markers for persistent specific expressive language delay in 3-4-year-olds.

BACKGROUND: Identifying 3-4-year-olds who are most at risk of persisting language difficulties, and possibly specific language impairment (SLI), is difficult due to the natural variation of language in young children. In older children, markers for SLI have been identified that differentiate between children with and without SLI. It is not known whether these markers can be used at an earlier age to identify children most at risk of persisting language difficulties. AIMS: To identify possible risk markers of current status that distinguish children who have specific expressive language delay (SELD) from the variation observed in normally developing children at age 3;0-4;0 and 4;0-5;0. To determine the most suitable measure(s) that would predict which children with SELD at age 3;0-4;0 were likely to have persistent expressive language delay (PELD) at age 4;0-5;0. METHODS & PROCEDURES: Forty-seven children with SELD and 47 children with typical language development (TLD) were assessed on language, nonverbal IQ and marker tasks at age 3;0-4;0 (baseline). Ninety-one children were reassessed on the measures one year later (follow-up). At both time points, the marker tasks were compared with a reference standard (Expressive Communication subscale (EC) of the Preschool Language Scale-3 (PLS-3) (UK)) to determine the most useful marker for identifying children with SELD. Possible predictors were examined to determine the most suitable measure(s) that would predict which children with SELD at baseline were likely to have PELD at follow-up. OUTCOME & RESULTS: A modified version of Recalling Sentences, a subtest of the Clinical Evaluation of Language Fundamentals (CELF)-Preschool UK, was the most useful marker for identifying children with SELD at baseline and at follow-up. Thirty-five (76.1%) of the 46 children with SELD at baseline had PELD at follow-up. Performance on the Auditory Comprehension (AC) and EC subscales of the PLS-3 (UK) and on modified Recalling Sentences at age 3;0-4;0 were predictors of PELD at age 4;0-5;0. CONCLUSIONS & IMPLICATIONS: A modified Recalling Sentences task was a good risk marker for SELD at age 3;0-4;0 and SELD at age 4;0-5;0. PLS-3 AC, PLS-3 EC and modified Recalling Sentences at baseline were the best predictors of PELD. The use of modified Recalling Sentences as a predictive marker requires confirmation.

[A review of dialogic reading intervention in children with developmental language disorder]. / Revisión de la intervención mediante lectura dialógica en niños con trastornos del desarrollo del lenguaje.

INTRODUCTION: Dialogic reading is one of the most used and studied techniques within the frame of shared book reading activities between children and adults. The current review aims to analyze its effects in late talkers and children with developmental language disorder, that is, not associated to other condition. METHODS: A systematic review of the literature was carried out following PRISMA Statement guidelines. RESULTS: The investigations reviewed show advances in children's lexical, grammatical and pragmatic indicators of language functioning. Likewise, changes are observed in the language of adults who apply the intervention, both in the use of dialogic reading strategies and in the grammatical and suprasegmental features of the language addressed to children. DISCUSSION: The evidence about the effectivity of dialogic reading in late talkers and children with developmental language disorders is promising but has important limitations that are mainly related to the design, social validity and reliability of interventions. Other remarkable issues relate to the books or materials employed and the measures used to assess its effectiveness.

Introducción: La lectura dialógica es una de las técnicas más empleadas y estudiadas en el marco de las actividades de lectura compartida de libros entre niños y adultos. La presente revisión sistemática tiene como objetivo principal analizar sus efectos en el lenguaje de niños hablantes tardíos o con trastorno del desarrollo del lenguaje, no asociados a otra condición. Métodos: Se llevó a cabo una revisión sistemática de la literatura siguiendo las orientaciones del PRISMA Statement, mediante la consulta con diferentes bases de datos. Resultados: Las investigaciones revisadas muestran progresos en el lenguaje de los niños en indicadores léxicos, gramaticales y pragmáticos. También se observan cambios en el lenguaje de los adultos que aplican la intervención, tanto en el uso de las estrategias propias de la técnica como en las características gramaticales y suprasegmentales de su lenguaje. Discusión: La evidencia sobre la efectividad de la lectura dialógica en niños con trastornos del desarrollo lenguaje es prometedora pero presenta limitaciones importantes relativas, fundamentalmente, al diseño, la validez social y la fiabilidad de las intervenciones. Otras cuestiones destacables hacen referencia a los libros o materiales con los que se interactúa y a las medidas empleadas para valorar su efectividad.

Effects in language development of young children with language delay during early intervention.

INTRODUCTION: In the Netherlands, early language intervention is offered to young children with Language Delay (LD). The intervention combines groupwise language intervention, individual speech and language therapy and parent-implemented language intervention. This study tests the hypothesis that children with LD show progress in their receptive and expressive language during intervention. Differences in language progress between age groups (< 36 months and ≥ 36 months at intervention start) were expected in favour of the younger group, which might be due to an earlier intervention start, a longer treatment duration or the potential presence of late talkers. METHODS: The study included 183 children with LD (45 children < 3 years of age at intervention start; mean age 32 months, 138 children ≥ 3 years; mean age 40 months). Receptive and expressive language was assessed with norm-referenced tests at intervention start and ending using Routine Outcome Monitoring. A repeated measures MANOVA was carried out to examine language progress and to compare the age groups on receptive syntax, receptive vocabulary, expressive syntax and expressive vocabulary. The Reliable Change Index was used to study individual progress. RESULTS: On average, children in both age groups showed significant improvement in all four language domains. The younger children showed more language progress than the older children in all four domains. When examining individual progress, most of the children displayed reliable improvement for expressive vocabulary. Most children developed in the same pace as their typically developing peers for receptive syntax, receptive vocabulary, and expressive syntax. CONCLUSIONS: Children stabilized or even improved language proficiency during the intervention, indicating that the language gap between these children and typically developing children did not widen further. Younger children displayed more language progress than older children in all four domains, but it is unclear what might explain this difference.

Assessing receptive verb knowledge in late talkers and autistic children: Advances and cautionary tales.

Purpose: Using eye-tracking, we assessed the receptive verb vocabularies of late talkers and typically developing children (Experiment 1) and autistic preschoolers (Experiment 2). We evaluated how many verbs participants knew and how quickly they processed the linguistic prompt. Method: Participants previewed two dynamic scenes side-by-side (e.g., "stretching" and "clapping") and were then prompted to find the target verb. Children's eye gaze behaviors were operationalized using established approaches in the field with modifications in consideration for the type of stimuli (dynamic scenes versus static images) and the populations included. Accuracy was calculated as a proportion of time spent looking to the target, and linguistic processing was operationalized as latency of children's first look to the target. Results: In Experiment 1, there were no group differences in the proportion of verbs known, but late talkers required longer to demonstrate their knowledge than typically developing children. Latency was predicted by age but not language abilities. In Experiment 2, autistic children's accuracy and latency were both predicted by receptive language abilities. Conclusion: Eye gaze can be used to assess receptive verb vocabulary in a variety of populations, but in operationalizing gaze behavior, we must account for between- and within-group differences. Bootstrapped cluster-permutation analysis is one way to create individualized measures of children's gaze behavior, but more research is warranted using an individual differences approach with this type of analysis. Finally, latency may not be a valid measure for dynamic scene stimuli for children under three years old.

Assessing receptive verb knowledge in late talkers and autistic children: advances and cautionary tales.

PURPOSE: Using eye-tracking, we assessed the receptive verb vocabularies of age-matched late talkers and typically developing children (experiment 1) and autistic preschoolers (experiment 2). We evaluated how many verbs participants knew and how quickly they processed the linguistic prompt. Our goal is to explore how these eye-gaze measures can be operationalized to capture verb knowledge in late talkers and autistic children. METHOD: Participants previewed two dynamic scenes side-by-side (e.g., "stretching" and "clapping") and were then prompted to find the target verb's referent. Children's eye-gaze behaviors were operationalized using established approaches in the field with modifications in consideration for the type of stimuli (dynamic scenes versus static images) and the populations included. Accuracy was calculated as a proportion of time spent looking to the target, and linguistic processing was operationalized as latency of children's first look to the target. RESULTS: In experiment 1, there were no group differences in the proportion of verbs known, but late talkers required longer to demonstrate their knowledge than typically developing children. Latency was predicted by age but not language abilities. In experiment 2, autistic children's accuracy and latency were both predicted by receptive language abilities. CONCLUSION: Eye gaze can be used to assess receptive verb vocabulary in a variety of populations, but in operationalizing gaze behavior, we must account for between- and within-group differences. Bootstrapped cluster-permutation analysis is one way to create individualized measures of children's gaze behavior, but more research is warranted using an individual differences approach with this type of analysis.

Towards a Characterization of Late Talkers: The Developmental Profile of Children with Late Language Emergence through a Web-Based Communicative-Language Assessment.

Children acquire language naturally, but there is variation in language acquisition patterns. Indeed, different internal and external variables play a role in acquiring language. However, there are open research questions about the contribution of different variables to language development. Moreover, with societal changes and due to the pandemic situation, there has been a growing interest in testing digitalization related to indirect language acquisition assessment. In this study, a web-based assessment survey was developed to (1) describe the relation between expressive vocabulary, Socio-Conversational Skills (SCS), gender, parental education, executive functions (EFs), and pretend play; (2) determine whether the survey can detect differences between late talkers (LTs) and children with typical language development; (3) identify children with "overall high" and "overall low" communicative-language scores to test the validity of expressive vocabulary as a main indicator to detect LTs. The parents of 108 Italian children (51 males) aged 24-36 months participated in the study. The results showed that expressive vocabulary correlates with measures of SCS (assertiveness and responsiveness) and is reliable in identifying LTs (d = 2.73). Furthermore, SCS and EFs contribute to better characterizing the developmental profile of children aged 24-36 months.

Describing communication profiles of low-risk preterm and full-term late talkers.

INTRODUCTION: Late talkers represent a heterogeneous population. We aimed to describe communication profiles of low-risk preterm and full-term late talkers according to their receptive and expressive vocabulary size, considering communicative, linguistic, cognitive, and motor skills, as well as biological and environmental risk factors. METHODS: Sixty-eight late talkers (33 born low-risk preterm and 35 full-term) were identified through a language screening at 30 months. Parents filled out the Italian Short Forms of the MacArthur Bates Communicative Development Inventories and the Socio Conversational Skills Rating Scales. Children were assessed with the Picture Naming Game test and the Bayley Scales of Infant and Toddler Development. RESULTS: A two-step cluster analysis identified three distinct profiles among late talkers according to their receptive and expressive vocabulary size. Severe late talkers (25%) showed less frequent use of pointing, limited verbal imitation, receptive vocabulary size, lexical and sentence production, responsiveness and assertiveness, and lower cognitive scores than mild late talkers (40%). Moderate late talkers (35%) showed less frequent verbal imitation, limited lexical and sentence production and lower cognitive scores than mild late talkers. Male gender was significantly more represented in the severe late profile, whereas other biological and environmental factors did not differ among the three profiles. CONCLUSIONS: Findings highlighted the relevance of assessing communicative, lexical, grammar, pragmatic, and cognitive skills to describe late talkers' profiles. A deeper investigation of phonological skills might also contribute to a further understanding of interindividual variability in this population.