Language experiences and vocabulary development in Dominican and Mexican infants across the first 2 years

We longitudinally investigated parental language context and infants' language experiences in relation to Dominican American and Mexican American infants' vocabularies. Mothers provided information on parental language context, comprising measures of parents' language background (i.e., childhood language) and current language use during interviews at infants' birth. Infants' language experiences were measured at ages 14 months and 2 years through mothers' reports of mothers' and fathers' engagement in English and Spanish literacy activities with infants and mothers' English and Spanish utterances during videotaped mother-infant interactions. Infants' vocabulary development at 14 months and 2 years was examined using standardized vocabulary checklists in English and Spanish. Both parental language context and infants' language experiences predicted infants' vocabularies in each language at both ages. Furthermore, language experiences mediated associations between parental language context and infants' vocabularies. However, the specific mediation mechanisms varied by language.     

The origin of language and relative roles of voice and gesture in early communication development

Both vocalization and gesture are universal modes of communication and fundamental features of language development. The gestural origins theory proposes that language evolved out of early gestural use. However, evidence reported here suggests vocalization is much more prominent in early human communication than gesture is. To our knowledge no prior research has investigated the rates of emergence of both gesture and vocalization across the first year in human infants. We evaluated the rates of gestures and speech-like vocalizations (protophones) in 10 infants at 4, 7, and 11 months of age using parent-infant laboratory recordings. We found that infant protophones outnumbered gestures substantially at all three ages, ranging from >35 times more protophones than gestures at 3 months, to >2.5 times more protophones than gestures at 11 months. The results suggest vocalization, not gesture, is the predominant mode of communication in human infants in the first year.     

A prelinguistic gestural universal of human communication

Several cognitive accounts of human communication argue for a language-independent, prelinguistic basis of human communication and language. The current study provides evidence for the universality of a prelinguistic gestural basis for human communication. We used a standardized, semi-natural elicitation procedure in seven very different cultures around the world to test for the existence of preverbal pointing in infants and their caregivers. Results were that by 10-14 months of age, infants and their caregivers pointed in all cultures in the same basic situation with similar frequencies and the same proto-typical morphology of the extended index finger. Infants' pointing was best predicted by age and caregiver pointing, but not by cultural group. Further analyses revealed a strong relation between the temporal unfolding of caregivers' and infants' pointing events, uncovering a structure of early prelinguistic gestural conversation. Findings support the existence of a gestural, language-independent universal of human communication that forms a culturally shared, prelinguistic basis for diversified linguistic communication.     

Gesture and early bilingual development

The relationship between speech and gestural proficiency was investigated longitudinally (from 2 years to 3 years 6 months, at 6-month intervals) in 5 French-English bilingual boys with varying proficiency in their 2 languages. Because of their different levels of proficiency in the 2 languages at the same age, these children's data were used to examine the relative contribution of language and cognitive development to gestural development. In terms of rate of gesture production, rate of gesture production with speech, and meaning of gesture and speech, the children used gestures much like adults from 2 years on. In contrast, the use of iconic and beat gestures showed differential development in the children's 2 languages as a function of mean length of utterance. These data suggest that the development of these kinds of gestures may be more closely linked to language development than other kinds (such as points). Reasons why this might be so are discussed.     

Gestural development and its relation to a child's early vocabulary

Gesture and language are tightly connected during the development of a child's communication skills. Gestures mostly precede and define the way of language development; even opposite direction has been found. Few recent studies have focused on the relationship between specific gestures and specific word categories, emphasising that the onset of one gesture type predicts the onset of certain word categories or of the earliest word combinations.The aim of this study was to analyse predicative roles of different gesture types on the onset of first word categories in a child's early expressive vocabulary. Our data show that different types of gestures predict different types of word production. Object gestures predict open-class words from the age of 13 months, and gestural routines predict closed-class words and social terms from 8 months. Receptive vocabulary has a strong mediating role for all linguistically defined categories (open- and closed-class words) but not for social terms, which are the largest word category in a child's early expressive vocabulary. Accordingly, main contribution of this study is to define the impact of different gesture types on early expressive vocabulary and to determine the role of receptive vocabulary in gesture-expressive vocabulary relation in the Croatian language.     

Exploring the Relation Between Memory, Gestural Communication, and the Emergence of Language in Infancy: A Longitudinal Study

The relationship between recall memory, visual recognition memory, social communication, and the emergence of language skills was measured in a longitudinal study. Thirty typically developing Swedish children were tested at 6, 9 and 14 months. The result showed that, in combination, visual recognition memory at 6 months, deferred imitation at 9 months and turn-taking skills at 14 months could explain 41% of the variance in the infants' production of communicative gestures as measured by a Swedish variant of the MacArthur Communicative Development Inventories (CDI). In this statistical model, deferred imitation stood out as the strongest predictor.     

The relationship between motor development,gestures and language production in the second year of life: A mediational analysis

This longitudinal study investigated the relationships between motor, gestural and linguistic abilities using two parent report instruments. Motor skills at 12 months significantly correlated with language production at 16, 20 and 23 months, but these associations were mediated by the use of representational gestures.     

Predictors of maternal language to infants during a picture book task in the home: Family SES, child characteristics and the parenting environment

This study investigated the contribution of child characteristics and parenting environment to the relationship between family SES/demographic characteristics and maternal language to infants. 1157 children were drawn from a representative sample of 1292 infants born to mothers in rural Appalachian counties and rural counties in southern minority U.S. communities. Mothers and their 6–8 month old babies were videotaped at home while talking about a wordless picture book. Mothers' language output and complexity were analyzed. Child temperament, age, and parenting environment (knowledge of child development and observed mother–child engagement) were predictors of maternal language. Furthermore, their inclusion reduced the magnitude of the association between demographic characteristics and maternal language. Tests of mediation suggested that the parenting environment partially mediates the relationship between SES/demographic characteristics and maternal language. Findings are discussed with respect to identifying proximal processes that explain how SES may exert its influence on the language of young children.     

DO INFANTS SHOW GENERALIZED IMITATION OF GESTURES?

Two experiments were conducted to investigate generalized imitation of manual gestures in 1- to 2-year-old infants. In Experiment 1, 6 infants were first trained four baseline matching relations (e.g., when instructed "Do this", to raise their arms after they saw the experimenter do so). Next, four novel gestures that the infants did not match in probe trials were selected as target behaviors during generalized imitation Test 1; models of these gestures were presented on unreinforced matching trials interspersed with intermittently reinforced baseline matching trials. None of the infants matched the target behaviors. To ensure that these behaviors were in the infants' motor skills repertoires, the infants were next trained to produce them, at least once, under stimulus control that did not include an antecedent model of the target behavior. In repeat generalized imitation trials (Test 2), the infants again failed to match the target behaviors. Five infants (3 from Experiment 1) participated in Experiment 2, which was identical to Experiment 1 except that, following generalized imitation Test 1, the motor-skills training was implemented to a higher criterion (21 responses per target behavior), and in a multiple-baseline, across-target-behaviors procedure. In the final generalized imitation test, 1 infant matched one, and another infant matched two target behaviors; the remaining 17 target behaviors still were not matched. The results did not provide convincing evidence of generalized imitation, even though baseline matching was well maintained and the target behaviors were in the infants' motor skills repertoires, raising the question of what are the conditions that reliably give rise to generalized imitation.     

Infants' early ability to segment the conversational speech signal predicts later language development: a retrospective analysis

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2 assessed linguistic and cognitive skills at 4-6 years of age for children who had participated in segmentation studies as infants. Children who had been able to segment words from fluent speech scored higher on language measures, but not general IQ, as preschoolers. Results suggest that speech segmentation ability is an important prerequisite for successful language development, and they offer potential for developing measures to detect language impairment at an earlier age.     

Eighteen-month-old human infants show intensive development in comprehension of different types of pointing gestures

This study explored children’s development in comprehending four types of pointing gestures with different familiarity. Our aim was to highlight human infants’ pointing comprehension abilities under the same conditions used for various animal species. Sixteen children were tested longitudinally in a two-choice task from 1 year of age. At the age of 12 and 14 months, infants did not exceed chance level with either of the gestures used. Infants were successful with distal pointing and long cross-pointing at the age of 16 months. By the age of 18 months, infants showed a high success rate with the less familiar gestures (forward cross-pointing and far pointing) as well. Their skills at this older age show close similarity with those demonstrated previously by dogs when using exactly the same testing procedures. Our longitudinal studies also revealed that in a few infants, the ability to comprehend pointing gestures is already apparent before 16 months of age. In general, we found large individual variation. This has been described for a variety of cognitive skills in human development and seems to be typical for pointing comprehension as well.     

Mother-child play and emerging social behaviors among infants from maltreating families

Mother-child play of 12-month-old infants (N=130) from maltreating (N=78) and non-maltreating (N=52) families was analyzed as a context that integrates infants' developing social and cognitive skills. Play was coded from semistructured and unstructured play paradigms. No group differences were found in infants' play maturity. Infants from abusing families demonstrated more imitative play than infants from non-maltreating families, and engaged in less independent play than infants from both neglecting and non-maltreating families, suggesting a delay in emerging social behaviors. Mothers from abusing and non-maltreating families differed in attention directing behaviors. Maternal behaviors predicted child play style variables, but did not mediate the effects of maltreatment. Findings discuss the influence of an early maltreating environment upon the development of the emergent self. Implications for early intervention are underscored.     

Form and function in early communication: language and pointing gestures

Pointing gestures of verbally advanced 2-year-olds were contrasted with those of less advanced peers, in order to examine the relationships of gesture to language during the acquisition of each. Hypotheses regarding the replacement of gestural functions by speech as verbal skills improve, regarding developmental correspondences between the two communicative domains, and regarding the independence of language acquisition from nonverbal developments were drawn from evolutionary, structuralist, and nativist viewpoints, respectively. Both formal and functional aspects of each communicative skill were measured, and were shown to be largely unrelated, particularly in the gestural domain. No evidence that language replaced gesture for communication in ontogeny was obtained. Correspondences between gesture and language occurred only between functional aspects of each, and the independence of developing language from gestural advances was suggested by the findings.     

Frequency of Gesture Use and Language in Typically Developing Prelinguistic Children

PurposeThe aim of this study was to examine the relationship between frequency of gesture use and language with a consideration for the effect of age and setting on frequency of gesture use in prelinguistic typically developing children.MethodParticipants included a total of 54 typically developing infants and toddlers between the ages of 9 months and 15 months separated into two age ranges, 9-12 months and 12-15 months. All participants were administered the Mullen’s Scale of Early Learning and two gesture samples were obtained: one sample in a structured setting and the other in an unstructured setting. Gesture samples were coded by research assistants blind to the purpose of the research study and total frequency and frequencies for the following gesture types were calculated: behavior regulation, social interaction, and joint attention (Bruner, 1983).ResultsResults indicated that both age and setting have a significant effect on frequency of gesture use and frequency of gesture is correlated to receptive and expressive language abilities; however, these relationships are dependent upon the gesture type examined.ConclusionsThese findings further our understanding of the relationship between gesture use and language and support the concept that frequency of gesture is related to language abilities. This is meaningful because gestures are one of the first forms of intentional communication, allowing for early identification of language abilities at a young age.     

Parents’ early book reading to children: Relation to children's later language and literacy outcomes controlling for other parent language input

It is widely believed that reading to preschool children promotes their language and literacy skills. Yet, whether early parent–child book reading is an index of generally rich linguistic input or a unique predictor of later outcomes remains unclear. To address this question, we asked whether naturally occurring parent–child book reading interactions between 1 and 2.5 years‐of‐age predict elementary school language and literacy outcomes, controlling for the quantity of other talk parents provide their children, family socioeconomic status, and children's own early language skill. We find that the quantity of parent–child book reading interactions predicts children's later receptive vocabulary, reading comprehension, and internal motivation to read (but not decoding, external motivation to read, or math skill), controlling for these other factors. Importantly, we also find that parent language that occurs during book reading interactions is more sophisticated than parent language outside book reading interactions in terms of vocabulary diversity and syntactic complexity.     

Early receptive and productive language skills in preterm and full-term 8-month-old infants

Early receptive and productive language skills were examined for preterm low birthweight infants and full-term normal birthweight infants from middle-class homes. Nineteen preterm infants and 19 full-term infants were observed in a laboratory setting at the gestationally corrected age of 8 months. To avoid the frequent confound between prematurity and low socioeconomic status, mothers of the two groups of infants were matched on educational levels. Regression analyses were used to assess the relative influence of infant cognitive skills, infant sociability, infant birth status, and the mothers' language input as possible predictors of infant receptive language and vocal behavior. Receptive language skills were associated with higher cognitive performance, greater sociability, and preterm birth. Productive language skills were associated with higher cognitive performance. On the basis of this research, the prognosis for language development in preterm infants raised in middle-class homes appears to be excellent.This research was aided by Social and Behavioral Sciences Research grant No. 12-11 from the March of Dimes Birth Defects Foundation and supported by DHHS Grant HD03352. Computing was provided by the Waisman Center Computing Facility at the University of Wisconsin-Madison. Donna Boylan, Sue DaPra, Maria Kleczewski, Michal Rubin, Susan Silverber, and Paula VanLaanan assisted with data collection.     

The predictive validity of nonverbal communicative skills in infants with perinatal hazards

This study investigated the predictive validity to 5 years of age of nonverbal communicative skills administered at 13 months. Subjects (N = 103) were Norwegian infants with birthweight below 1501 gms. The predictors included infant competence assessed by the Early Social-Communication Scales (ESCS). Cognitive competence at 2 years was measured by the Bayley Mental Development Scale, and at 3 and 5 years by the Stanford-Binet Intelligence Scale: Fourth Edition (SB:FE). Language competence at 2 and 3 years was assessed by the Reynell Developmental Language Scales, and at 5 years by a verbal comprehension factor derived from the SB:FE. Partial correlations and multiple regression analyses suggest that the infants' initiation of communication was related to cognitive ability and language skills up to 5 years of age. In particular, joint attention was the most consistent predictor of the subsequent competencies. The Bayley cognitive index was overruled as a predictor when used in combination with initiation of joint attention.     

Infants' responses to arm restraint at 2 and 6 months: a longitudinal study

This study examined the continuity, stability, and change of infants' responses to a frustrating event (i.e., arm restraint) between 2 and 6 months in terms of both negative reactivity and its regulation. Fifty-two healthy, full-term infants and their mothers participated in an arm restraint procedure. Infant behaviors were observed and coded at 3-s intervals. The results showed that infants' reactivity to frustration and their ability to regulate such reactivity significantly changed in level over time. Individual differences in frustration reactivity were stable across the two ages; two regulatory behaviors (i.e., orientation to mother and avoidance) could be observed in the same percentage of babies at both 2 and 6 months. At 6 months, several significant associations between frustration reactivity and infant regulatory behaviors emerged. These findings suggest that the arm restraint procedure may be usefully employed to study individual differences in infants as young as 2 months of age.     

Developmental change in the neuropsychological functioning of very low birth weight infants

Research on very low birth weight (VLBW) infants has not carefully evaluated developmental patterns of neurological and neuropsychological functioning across time. This study reports on a broad range of developmental outcomes for VLBW infants of low (LR, n = 116) and high (HR, n = 84) medical risk compared to full term infants (FT, n = 120) across 6, 12, and 24 months of age. While low risk infants showed initial delays in most areas, faster rates of change in motor and neurological development resulted in catch-up by 2 years of age as compared to the FT infants. The lack of acceleration in development of mental skills demonstrates a persistent lag in this area. In contrast, HR infants showed initial delays in all areas as compared to both LR and FT infants with slower rates of change in mental and expressive language skills. Although faster rates of change were evident for HR infants in motor, neurological, and receptive language skills, scores in these areas remain lower than those for the LR and FT infants. The absence of accelerated rates of development for certain VLBW infants has implications for prognosis and patient access to early intervention services.     

Dyadic processes between mothers and preterm infants: Development at ages 2 to 5 years

In order to identify antecedents to cognitive, language, and social competence from 2 to 5 years of age in preterm children at biological and social risk, this study used multiple procedures, administered in the laboratory, at 13 and 20 months, to measure components of the social interactions between 51 mothers and their preterm infants. Two variables, maternal responsiveness to infant vocalization and infant irritability, were found to be significant predictors of later competence. Whereas greater maternal responsiveness, as expected, led to increased language and social skills, greater infant irritability during stressful situations also foretold later increased competence in expressive and receptive language and social cognition. Children born at higher birthweights and with longer gestations were more likely to be more irritable than those born at very low birthweights. The findings suggest different implications for negative affect in preterms who have experienced respiratory distress as contrasted to full-term children, but indicate similar positive consequences for maternal verbal responsiveness.