Noun and Verb Production in Maternal and Child Language: Continuity, Stability, and Prediction across the Second Year of Life

Maternal mind-mindedness and communicative functions in free-play and mealtime contexts: Stability, continuity and relations with child language at 16 months

The present study aimed at investigating the contextual stability, the contextual continuity and the concurrent associations between maternal measures (general language, communicative functions and mind-mindedness) and child measures (total number of word types and tokens) in two different contexts, free-play and mealtime. To this purpose, the interactions occurring between 25 mothers and their 16-month-old children in each context were video-recorded, transcribed and later coded for the selected measures. Significant contextual stability was observed in the mothers' production of general language measures (total number of utterances, total number of words and MLU), in the children's production of word types and tokens, and in some communicative functions (Tutorial, Control and Asynchronous). No contextual stability was found for the mothers' production of attuned mind-related comments. For continuity, both mothers and children produced more utterances and words in the free-play than in the mealtime context; the production of attuned mind-related comments and the use of the Control function were also more frequent in the free-play context. Lastly, the analysis of the concurrent correlations indicated that, especially in the mealtime context, the number of words produced by children was positively associated with the number of words produced by mothers and by their use of the Tutorial and Didactic functions, but negatively associated with their use of the Control function. The mothers' production of attuned mind-related comments bore no relation with children's expressive language. Similarities and differences with previous findings are discussed.

Understanding Child-Directed Speech Around Book Reading in Toddler Classrooms: Evidence From Early Head Start Programs

Child-directed speech (CDS), which can help children learn new words, has been rigorously studied among infants and parents in home settings. Yet, far less is known about the CDS that teachers use in classrooms with toddlers and children’s responses, an important question because many toddlers, particularly in high-need communities, attend group-care settings. This exploratory study examines the linguistic environment during teacher-led book readings in American Early Head Start classrooms serving 2-year-olds from households in poverty. Seven teachers in four classrooms were trained to emphasize target words while reading story and informational books. We first analyzed the nature and quality of their book readings from a macro-level, exploring global instructional quality [Classroom Assessment Scoring System (CLASS)] and linguistic complexity [i.e., diversity of vocabulary (D) and sophistication of syntax (MLU-w)], and we also examined micro-level teacher-child talk strategies and use of target words. Compared to prior research, these classrooms had similar global quality and syntactic complexity, although less lexical diversity. Exploratory results also revealed three distinct teacher talk patterns—teachers who emphasized (1) comments, (2) questions, and (3) a balance of the two. Question-focused teachers had more adult and child talk during reading, as well as more repetitions of target words, and stronger CLASS Engaged Support for Learning. However, comment-focused teachers used more diverse vocabulary and had stronger CLASS Emotional and Behavioral Support. Results illuminate the nature and quality of CDS in toddler classrooms, particularly in the context of an intervention emphasizing target vocabulary words, and highlight applications for professional development and questions for further research.

Neural Speech Encoding in Infancy Predicts Future Language and Communication Difficulties

Purpose This study aimed to construct an objective and cost-effective prognostic tool to forecast the future language and communication abilities of individual infants. Method Speech-evoked electroencephalography (EEG) data were collected from 118 infants during the first year of life during the exposure to speech stimuli that differed principally in fundamental frequency. Language and communication outcomes, namely four subtests of the MacArthur-Bates Communicative Development Inventories (MCDI)-Chinese version, were collected between 3 and 16 months after initial EEG testing. In the two-way classification, children were classified into those with future MCDI scores below the 25th percentile for their age group and those above the same percentile, while the three-way classification classified them into < 25th, 25th-75th, and > 75th percentile groups. Machine learning (support vector machine classification) with cross validation was used for model construction. Statistical significance was assessed. Results Across the four MCDI measures of early gestures, later gestures, vocabulary comprehension, and vocabulary production, the areas under the receiver-operating characteristic curve of the predictive models were respectively .92 ± .031, .91 ± .028, .90 ± .035, and .89 ± .039 for the two-way classification, and .88 ± .041, .89 ± .033, .85 ± .047, and .85 ± .050 for the three-way classification (p < .01 for all models). Conclusions Future language and communication variability can be predicted by an objective EEG method that indicates the function of the auditory neural pathway foundational to spoken language development, with precision sufficient for individual predictions. Longer-term research is needed to assess predictability of categorical diagnostic status. Supplemental Material https://doi.org/10.23641/asha.15138546.

Tailoring the Input to Children's Needs: The Use of Fine Lexical Tuning in Speech Directed to Normally Hearing Children and Children With Cochlear Implants

Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed speech (IDS) addressed to congenitally deaf infants who received a cochlear implant (CI) early in life (<2 years of age) in comparison with children with normal hearing (NH). The longitudinal pattern of parents' utterance length in the initial stages of the child's lexical development was examined. Parents' utterances containing the words the children eventually acquired in the earliest developmental stages were selected and their MLU (Mean Length of Utterance) was measured.

Method: Transcriptions of monthly recordings of spontaneous interactions of 10 CI children and 30 NH children with their parents were analyzed. The children with CI were followed from the moment their device was switched on, and the NH children from the age of 6 months onwards. A total of 57,846 utterances of parents of CI children and 149,468 utterances of parents of NH children were analyzed.

Results: IDS addressed to children with NH and children with CI exhibits fine lexical tuning: parents adjust the MLU of the utterances that contain the words that children are on the verge of producing themselves. More specifically, the parents' mean length of those utterances decreased in relation to the point when the children began using the item. Consequently, the number of occurrences in isolation of the lexical item increased. The speech addressed to all the children exhibited this phenomenon, but it was significantly more strongly present in speech addressed to the children with CI.

Conclusions: The speech addressed to children with NH and CI is characterized by fine lexical tuning and a high incidence of single-word utterances in the period leading up to the children's first use of words in speech production. Notwithstanding striking commonalities, IDS addressed to children with a hearing impairment is markedly different, which suggests that parents take this specific character of the children into account.

Stabilities of Infant Behaviors and Maternal Responses to Them

Consistency in the order of individuals in a group across substantial lengths of time-stability-is a central concept in developmental science for several reasons. Stability underscores the meaningfulness of individual differences in psychological phenomena; stability informs about the origins, nature, and overall developmental course of psychological phenomena; stability signals individual status and so affects the environment, experience, and development; stability has both theoretical and clinical implications for individual functioning; and stability helps to establish that a measure constitutes a consequential individual-differences metric. In this three-wave prospective longitudinal study (Ns = 40 infants and mothers), we examined stabilities of individual variation in multiple infant behaviors and maternal responses to them across infant ages 10, 14, and 21 months. Medium to large effect size stabilities in infant behaviors and maternal responses emerged, but both betray substantial amounts of unshared variance. Documenting the ontogenetic trajectories of infant behaviors and maternal responses helps to elucidate the nature and structure of early human development.

Features of speech in German and US-American mother-toddler dyads during toy play and book-reading

Previous research indicates that features of speech during mother-toddler interactions are dependent on the situational context. In this study, we explored language samples of 69 mother-toddler dyads collected during standardized toy play and book-reading situations across two countries, Germany and the United States (US). The results showed that features of speech differed across situational contexts. However, situational differences were mostly found among the sample from the US but not from Germany. Few significant associations between mothers' and toddlers' language variables were found. Findings are discussed with regard to variations in language across situations and countries.

Infant-directed speech as a simplified but not simple register: a longitudinal study of lexical and syntactic features

Infant-directed speech (IDS) is a specific register that adults use to address infants, and it is characterised by prosodic exaggeration and lexical and syntactic simplification. Several authors have underlined that this simplified speech becomes more complex according to the infant's age. However, there is a lack of studies on lexical and syntactic modifications in Italian IDS during the first year of an infant's life. In the present study, 80 mother-infant dyads were longitudinally observed at 3, 6, 9, and 12 months during free-play interactions. Maternal vocal productions were subsequently coded. The results show an overall low lexical variability and syntactic complexity that identify speech to infants as a simplified register; however, the high occurrence of complex items and well-structured utterances suggests that IDS is not simple speech. Moreover, maternal IDS becomes more complex over time, but not linearly, with a maximum simplification in the second half of the first year.

Continuity and Stability in Development

Developmental science is centrally concerned with both consistency and change in characteristics through time. Consistency and change in development are tracked by group mean level continuity and individual order stability. Group mean level and individual order consistency and change are both developmentally informative and can co-exist conceptually and empirically as the two are partially orthogonal perspectives on development. Continuity and stability are broadly applicable to characteristics of the individual, dyad, and environment. Significantly, absent the distinctions we draw between mean level continuity and individual order stability, researchers who use the terms willy-nilly leave their readers in the dark as to which key feature of development is meant. In this article, we distinguish the two types of consistency and change, their measurement, importance, moderation, and implications.

Do early noun and verb production predict later verb and noun production? Theoretical implications

Many studies have addressed the question of the relative dominance of nouns over verbs in the productive vocabularies of children in the second year of life. Surprisingly, cross-class (noun-to-verb and verb-to-noun) relations between these two lexical categories have seldom been investigated. The present longitudinal study employed observational and parent-report data obtained from thirty mother-child dyads at 1;4, 1;8, and 2;0 to examine this issue. Both the Natural Partitions/Relational Relativity (NP/RR) hypothesis and the Emergentist Coalition Model (ECM) predict that having an initial repertoire of common nouns should facilitate the acquisition of novel verbs, whereas only the ECM suggests that children exploit the syntactic and semantic constraints of known verbs to infer the meaning of novel nouns. In line with the ECM, hierarchical regression analyses indicated that the percentages of nouns produced by children at 1;4 predicted later verbs at 1;8, whereas the percentages of verbs produced at 1;8 predicted later nouns at 2;0.