Examining the relationship of acetaminophen use during pregnancy with early language development in children.

BACKGROUND: Acetaminophen is the only analgesic considered safe for use throughout pregnancy. Recent studies suggest that use during pregnancy may be associated with poorer neurodevelopmental outcomes in children, but few have examined language development. METHODS: The Illinois Kids Development Study is a prospective birth cohort in east-central Illinois. Between December 2013 and March 2020, 532 newborns were enrolled and had exposure data available. Participants reported the number of times they took acetaminophen six times across pregnancy. Language data were collected at 26.5-28.5 months using the MacArthur-Bates Communicative Development Inventories (CDI; n = 298), and 36-38 months using the Speech and Language Assessment Scale (SLAS; n = 254). RESULTS: Taking more acetaminophen during the second or third trimester was associated with marginally smaller vocabularies and shorter utterance length (M3L) at 26.5-28.5 months. More acetaminophen use during the third trimester was also associated with increased odds of M3L scores ≤25th percentile in male children. More use during the second or third trimester was associated with lower SLAS scores at 36-38 months. Third trimester use was specifically related to lower SLAS scores in male children. CONCLUSIONS: Higher prenatal acetaminophen use during pregnancy may be associated with poorer early language development. IMPACT: Taking more acetaminophen during pregnancy, particularly during the second and third trimesters, was associated with poorer scores on measures of language development when children were 26.5-28.5 and 36-38 months of age. Only male children had lower scores in analyses stratified by child sex. To our knowledge, this is the first study that has used a standardized measure of language development to assess the potential impact of prenatal exposure to acetaminophen on language development. This study adds to the growing body of literature suggesting that the potential impact of acetaminophen use during pregnancy on fetal neurodevelopment should be carefully evaluated.

Parent Responsivity, Language Input, and the Development of Simple Sentences.

This study explored responsive and linguistic parent input features during parent-child interactions and investigated how four input categories related to children's production of diverse, simple sentences. Of primary interest was parent use of responsive, simple declarative input sentences. Responsive and linguistic features of parent input to 20 typically developing toddlers at 1;9 were coded during play in a laboratory playroom, then classified into four input categories: responsive, declarative, responsive declarative, and neither responsive nor simple declarative. The percentage of each input category was related to child sentence diversity at 2;6 using Spearman correlations. Parent use of responsive declarative and declarative utterances were both rare. Responsive input was positively correlated with child sentence diversity, and the neither category was negatively correlated with child sentence diversity. The findings provide new support for the importance of balanced conversational turns. Implications for defining both how input is delivered and its linguistic content are discussed.

Characterizing the Richness of Maternal Input for Word Learning in Neurogenetic Disorders.

Promoting language abilities, including early word learning, in children with neurogenetic disorders with associated language disorders, such as Down syndrome (DS) and fragile X syndrome (FXS), is a main concern for caregivers and clinicians. For typically developing children, the quality and quantity of maternal language input and maternal gesture use contributes to child word learning, and a similar relation is likely present in DS and FXS. However, few studies have examined the combined effect of maternal language input and maternal gesture use on child word learning. We present a multidimensional approach for coding word-referent transparency in naturally occurring input to children with neurogenetic disorders. We conceptualize high-quality input from a multidimensional perspective, considering features from linguistic, interactive, and conceptual dimensions simultaneously. Using case examples, we highlight how infrequent the moments of word-referent transparency are for three toddlers with DS during play with their mothers. We discuss the implications of this multidimensional framework for children with DS and FXS, including the clinical application of our approach to promote early word learning for these children.

Diversity matters: parent input predicts toddler verb production.

The contribution of parent input to children's subsequent expressive verb diversity was explored in twenty typically developing toddlers with small verb lexicons. Child developmental factors and parent input measures (i.e. verb quantity, verb diversity, and verb-related structural cues) at age 1;9 were examined as potential predictors of children's verb production in spontaneous language samples at age 2;3. Parent verb input diversity, rather than input quantity, was the primary input factor contributing to children's subsequent verb diversity. Regression analysis showed that verb diversity in parent input at age 1;9 accounted for 30% of the variance in children's verb production six months later, with children's total vocabulary size at age 1;9 accounting for an additional 16% of the variance. These findings demonstrate the relative contributions of developmental and input factors to individual differences in toddlers' language development and establish the importance of input diversity to verb acquisition.

A Brief Intervention to Teach Parents Naturalistic Language Facilitation Strategies.

PURPOSE: This proof of concept study assessed the feasibility of a novel approach to teaching parents naturalistic language facilitation strategies in a single session. We investigated whether parents could learn to use the See and Say Sequence, which integrated responsive and language modeling strategies and measured the impacts that this intervention had on features of their input. METHOD: Fourteen parent-child dyads participated in the study. Children ranged from 15 to 23 months of age and produced between three and 135 words. Five parents had concerns about their children's rate of language development. Parents were taught the See and Say Sequence during a brief single session (M = 18.98 min, SD = 2.65 min) using the Teach-Model-Coach-Review instructional process. We analyzed parents' use of the three See and Say Sequence components, total number of utterances, and mean turn length, as well as responsive and linguistic features of parent input before and after the brief intervention. RESULTS: Following intervention, parents significantly increased their use of the three See and Say Sequence components and decreased their total number of utterances and mean turn length. In addition, the use of the See and Say Sequence components substantially altered the overall composition of parent input. CONCLUSIONS: The results of this preliminary study demonstrate the feasibility of the See and Say Sequence in teaching responsive and language modeling strategies in a single session. We discuss the potential use and future evaluation of the See and Say Sequence as an option for early intervention service delivery.

Caregiver Language Input Supports Sentence Diversity in Young Children With Autism Spectrum Disorder.

PURPOSE: Sentence diversity is a measure of early language development that has yet to be applied to individuals with autism spectrum disorder (ASD). The primary aim of this study was to identify whether children with ASD show change in sentence diversity over 6 months of treatment with Naturalistic Developmental Behavioral Intervention (NDBI). The secondary aim was to examine possible predictors of changes in children's sentence diversity, including caregiver use of NDBI strategies, naturally occurring instances of caregiver Toy Talk, and child characteristics. METHOD: Fifty children with ASD (ages 2-4 years) and their caregivers, who were receiving NDBI, engaged in two 10-min video-recorded play interactions, 6 months apart. Child speech was transcribed and coded for sentence diversity. Caregiver input was transcribed and coded for naturally occurring Toy Talk. Zero-inflated negative binomial mixed models were used to explore predictors of change in child sentence diversity. RESULTS: Children's sentence diversity improved over time. Changes in caregiver NDBI strategy use and caregiver baseline Toy Talk were significant predictors of changes in sentence diversity, as were baseline age, nonverbal ratio IQ, and child sex. Additionally, a significant interaction of caregiver baseline Toy Talk and change in caregiver NDBI strategies emerged; the effect of caregiver baseline Toy Talk on children's sentence diversity change was stronger when NDBI strategy use improved. CONCLUSIONS: Sentence diversity is a developmentally sensitive measure of language development in ASD. NDBI strategies that facilitate reciprocal social communication, combined with input composed of declarative sentences with noun or third-person pronoun subjects, may provide optimal support for children's sentence development.

Exploring Sentence Diversity at the Boundary of Typical and Impaired Language Abilities.

Purpose This review article summarizes programmatic research on sentence diversity in toddlers developing language typically and explores developmental patterns of sentence diversity in toddlers at risk for specific language impairment. Method The first half of this review article presents a sentence-focused approach to language assessment and intervention and reviews findings from empirical studies of sentence diversity. In the second half, subject and verb diversity in three simple sentence types are explored in an archival database of toddlers with varying levels of grammatical outcomes at 36 months of age: low average, mild/moderate delay, and severe delay. Results Descriptive findings from the archival database replicated previous developmental patterns. All toddlers with low-average language abilities produced diverse simple sentences by 30 months of age and exhibited greater sentence diversity with first-person I-subjects before third-person subjects. Third-person subject diversity emerged in a developmental sequence, increasing in one-argument copula contexts and one-argument subject-verb sentences before two-argument subject-verb-object sentences. This developmental pattern held across all three outcome groups. Third-person subjects were least diverse for children with severe grammatical delays and were absent in all sentence contexts for two children with severe delays at 36 months. Conclusions Sentence diversity increases gradually and expands in predictable patterns. Understanding these developmental patterns may help identify and treat children who display unexpected difficulty combining different subjects and verbs in flexible ways. Supplemental Material and Presentation Video https://doi.org/10.23641/asha.12915320.

The growth of tense productivity.

PURPOSE: This study tests empirical predictions of a maturational model for the growth of tense in children younger than 36 months using a type-based productivity measure. METHOD: Caregiver-child language samples were collected from 20 typically developing children every 3 months from 21 to 33 months of age. Growth in the productivity of tense morphemes, centered at 21 months, was examined using hierarchical linear modeling. The empirical Bayes residuals from 21- to 30-month productivity growth trajectories predicted children's accuracy of tense marking at 33 months. RESULTS: A random effects quadratic growth model with no intercept best characterized the growth of tense marking between 21 and 30 months. Average development was characterized by slow instantaneous linear growth of less than 1 morpheme per month at 21 months and acceleration overall. Significant variation around this trend was also evident. Children's linear and quadratic empirical Bayes residuals together predicted 33-month accuracy scores (r = .672, p = .008). CONCLUSIONS: Acceleration and variation about this trend are consistent with maturational models of language acquisition. With an empirically sound characterization of early variation in morphosyntactic growth rates, future investigations can more rigorously test hypotheses regarding biological, environmental, and developmental contributions to the acquisition of morphosyntax.

Let's Be Explicit About the Psycholinguistic Bases of Developmental Measures: A Response to Leonard, Haebig, Deevy, and Brown (2017).

Purpose: The purpose of this letter is to clarify the psycholinguistic underpinnings of the tense marker total and tense agreement productivity score and to extend the discussion of when composite diversity and productivity measures are best used. Conclusion: We encourage the use of composite diversity and productivity measures when assessing grammar early in development, but we discourage the use of composite accuracy measures until children demonstrate emergence of diverse tense/agreement morphemes across a sufficient number of low-frequency sentence frames.

Sentence Diversity in Early Language Development: Recommendations for Target Selection and Progress Monitoring.

Purpose: This clinical focus article describes how to assess and when to target diverse, simple sentences as part of early language intervention. Method: The theoretical foundations and clinical motivations for assessing sentence diversity based on unique combinations of subjects and verbs are explained, followed by a description of how to compute the measure. Sentence diversity is then related to familiar developmental measures of lexical diversity, utterance length, and grammatical complexity in a sample of 40 typically developing toddlers at 30 months of age. Descriptive and correlational analyses are used to demonstrate how sentences become more diverse as utterances also become longer and more complex. Conclusions: The ability to produce simple sentences with diverse subject-verb combinations is proposed as a general developmental expectation for toddlers at 30 months of age. All 40 children produced at least 10 different subject-verb combinations in 30 min of parent-toddler conversation. Sentence diversity is also associated with familiar developmental measures. Recommendations are provided for using the measure of sentence diversity to inform treatment planning and monitor progress for young children with language disorders. Supplemental Material: https://doi.org/10.23641/asha.5895976.

Input Subject Diversity Accelerates the Growth of Tense and Agreement: Indirect Benefits From a Parent-Implemented Intervention.

Purpose: This follow-up study examined whether a parent intervention that increased the diversity of lexical noun phrase subjects in parent input and accelerated children's sentence diversity (Hadley et al., 2017) had indirect benefits on tense/agreement (T/A) morphemes in parent input and children's spontaneous speech. Method: Differences in input variables related to T/A marking were compared for parents who received toy talk instruction and a quasi-control group: input informativeness and full is declaratives. Language growth on tense agreement productivity (TAP) was modeled for 38 children from language samples obtained at 21, 24, 27, and 30 months. Parent input properties following instruction and children's growth in lexical diversity and sentence diversity were examined as predictors of TAP growth. Results: Instruction increased parent use of full is declaratives (ηp2 ≥ .25) but not input informativeness. Children's sentence diversity was also a significant time-varying predictor of TAP growth. Two input variables, lexical noun phrase subject diversity and full is declaratives, were also significant predictors, even after controlling for children's sentence diversity. Conclusions: These findings establish a link between children's sentence diversity and the development of T/A morphemes and provide evidence about characteristics of input that facilitate growth in this grammatical system.

Input Subject Diversity Enhances Early Grammatical Growth: Evidence from a Parent-Implemented Intervention.

PURPOSE: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity. METHOD: Child growth in third person sentence diversity was modeled from 21 to 30 months (n = 38) in conversational language samples obtained at 21, 24, 27, and 30 months. Treatment parents (n = 19) received instruction on strategies designed to increase lexical NP subjects (e.g., The baby is sleeping.). Instruction consisted of one group education session and two individual coaching sessions which took place when children were approximately 22 to 23 months of age. RESULTS: Treatment substantially increased parents' lexical NP subject tokens and types (ηp2 ≥ .45) compared to controls. Children's number of different words was a significant predictor of sentence diversity in the analyses of group treatment effects and individual input effects. Treatment condition was not a significant predictor of treatment effects on children's sentence diversity, but parents' lexical NP subject types was a significant predictor of children's sentence diversity growth, even after controlling for children's number of different words over time. CONCLUSIONS: These findings establish a link between subject diversity in parent input and children's early grammatical growth, and the feasibility of using relatively simple strategies to alter this specific grammatical property of parent language input.

Individual differences in the onset of tense marking: a growth-curve analysis.

The purpose of this study was to explore individual differences in children's tense onset growth trajectories and to determine whether any within- or between-child predictors could account for these differences. Twenty-two children with expressive vocabulary abilities in the low-average to below-average range participated. Sixteen children were at risk for specific language impairment (SLI), and 6 children had low-average language abilities. Spontaneous language samples, obtained at 3-month intervals between 2;0 and 3;0, were analyzed to examine change in a cumulative productivity score for 5 tense morphemes: third person singular present, past tense, copula BE, auxiliary BE, and auxiliary DO. Hierarchical linear modeling was used to model intercept and linear growth at 30 months and quadratic growth overall. A growth model that included mean length of utterance (MLU) and MLU growth better explained within-child productivity score growth trajectories than a parallel model with vocabulary and vocabulary growth. Significant linear growth in productivity scores remained even after a control for MLU was in place. When between-child predictors were added in the final conditional model, only positive family history approached statistical significance, improving the overall estimation of the model's growth parameters. The findings support theoretical models of language acquisition that claim relative independence of tense marking from other more general aspects of vocabulary development and sentence length. The trends for family history are also consistent with proposals implicating faulty genetic mechanisms underlying developmental language disorders. Systematic use of familial risk data is recommended in future investigations examining the relationship between late-talking children and children at risk for SLI.

Toddlers' Verb Lexicon Diversity and Grammatical Outcomes.

PURPOSE: The goals of this study were to quantify longitudinal expectations for verb lexicon growth and to determine whether verb lexicon measures were better predictors of later grammatical outcomes than noun lexicon measures. METHOD: Longitudinal parent-report measures from the MacArthur-Bates Communicative Development Inventory (Fenson et al., 2007) from ages 21 to 30 months from an archival database were used to model growth in common noun and verb lexicon size for 45 typically developing toddlers. Communicative Development Inventory growth coefficients and 24-month measures of lexical diversity from spontaneous language samples were used to predict 30-month grammatical outcomes on the Index of Productive Syntax (Scarborough, 1990). RESULTS: Average verb growth was characterized by 50.57 verbs at 24 months, with linear growth of 8.29 verbs per month and deceleration overall. Children with small verb lexicons or slow linear growth at 24 months accelerated during this developmental period. Verb lexicon measures were better predictors of grammatical outcomes than noun lexicon measures, accounting for 47.8% of the variance in Index of Productive Syntax scores. Lexical verb diversity in spontaneous speech emerged as the single best predictor. CONCLUSION: Measures of verb lexicon size and diversity should be included as part of early language assessment to guide clinical decision making with young children at risk for language impairment.

The onset of tense marking in children at risk for specific language impairment.

PURPOSE: The purpose of this study was to develop and evaluate measures reflecting the onset of tense marking for children between the ages of 2;0 (years;months) and 3;0. METHOD: The validity of 4 cumulative measures of tense marker emergence and productivity was evaluated relative to existing measures of early grammatical development in a sample of 20 children followed longitudinally. Fourteen children were at risk for specific language impairment (AR-SLI group), and 6 children had low average language abilities (LA group). RESULTS: All measures of onset were highly correlated with the traditional measures; however, children's progress toward mastery of grammatical tense marking was best explained by the productivity of their tense marking systems. Finally, the onset measures imposing productivity requirements best differentiated children in the LA group from those in the AR-SLI group. CONCLUSIONS: The clinical implications for using the late onset of tense marking to improve the early identification of SLI are discussed.

Approaching early grammatical intervention from a sentence-focused framework.

PURPOSE: In this response to Kamhi (2014), a sentence-focused framework is presented to help clinicians select treatment targets as part of a comprehensive approach to early grammatical intervention. METHOD: The literature on the relationship between lexical verbs, sentence structure, and tense/agreement morphemes is reviewed, and developmental expectations are summarized for each. CONCLUSION: Given that the sentence is the basic unit of grammar, the author concludes that early grammatical intervention should promote sentence development for young children at risk for language disorders. Recommendations for selecting and facilitating grammatical objectives in early childhood are provided.

Toy talk: simple strategies to create richer grammatical input.

PURPOSE: The purpose of this initial feasibility study was to determine whether brief instruction in toy talk would change grammatical properties of adult language, specifically 3rd person lexical noun phrase (NP) subjects. METHOD: Eighteen college students participated in the study. The use of 3rd person subjects was examined before and after instruction on toy talk strategies (i.e., talk about the toys, give the item its name). Change in the input informativeness for tense (i.e., the proportion of verb forms marked for tense out of all verb forms) was also examined, although adults were not instructed on use of tense/agreement morphemes. RESULTS: Following instruction, statistically significant increases with large effect sizes were observed for use of 3rd person subjects, lexical NP subjects, and input informativeness for tense (Cohen's d = 1.20, 2.08, and 0.89, respectively). CONCLUSIONS: These findings demonstrate that young adults can learn these simple strategies with relatively brief instruction, and the use of toy talk also changes the richness of tense/agreement marking in adult language input. Considerations for incorporating toy talk into existing language modeling practices and future plans for evaluating the efficacy of toy talk are discussed.

Growth of finiteness in the third year of life: replication and predictive validity.

PURPOSE: The authors of this study investigated the validity of tense and agreement productivity (TAP) scoring in diverse sentence frames obtained during conversational language sampling as an alternative measure of finiteness for use with young children. METHOD: Longitudinal language samples were used to model TAP growth from 21 to 30 months of age for 37 typically developing toddlers. Empirical Bayes (EB) linear and quadratic growth coefficients and child sex were then used to predict elicited grammar composite scores on the Test of Early Grammatical Impairment (TEGI; Rice & Wexler, 2001) at 36 months. RESULTS: A random-effects quadratic model with no intercept best characterized TAP growth, replicating the findings of Rispoli, Hadley, and Holt (2009). The combined regression model was significant, with the 3 variables accounting for 55.5% of the variance in the TEGI composite scores. CONCLUSION: These findings establish TAP growth as a valid metric of finiteness in the 3rd year of life. Developmental and theoretical implications are discussed.

Are some parents' interaction styles associated with richer grammatical input?

PURPOSE: Evidence for tense marking in child-directed speech varies both across languages ( Guasti, 2002; Legate & Yang, 2007) and across speakers of a single language ( Hadley, Rispoli, Fitzgerald, & Bahnsen, 2011). The purpose of this study was to understand how parent interaction styles and register use overlap with the tense-marking properties of child-directed speech. This study investigated how parent interaction style, measured by utterance function, and parent register use when asking questions interacted with verb forms in child-directed input to identify interaction styles associated with the richest grammatical input. METHOD: Participants were 15 parent-toddler dyads. The communicative function of parent utterances and the form of their questions were coded from language samples of parent-child play when children were 21 months of age. Verbs were coded for linguistic form (e.g., imperative, modal, copula). RESULTS: Directives and reduced questions were both negatively related to input informativeness (i.e., the proportion of unambiguous evidence for tense). Other-focused descriptives were positively related to input informativeness. CONCLUSION: Predictable overlap existed between the characteristics of parents' interaction styles and register use and their input informativeness. An other-focused descriptive style most strongly related to richer evidence for the +Tense grammar of English.