Sociolinguistic contexts of the preschool

Two studies were conducted to determined the effects of specific learning centers on preschoolers' functional uses of language. In Study 1, preschoolers in three separate same-age classrooms (2-, 3-, and 5-year-olds) were observed on a time sampling scheduling during their free play periods for four weeks. Preschoolers' individual utterances were coded as serving one or more than one function; functions were defined following Halliday. The housekeeping and block centers tended to elicit the most individual and multifunctional utterances. The fantasy play and social interaction among children in these centers were thought to be responsible for this mature use of language.In Study 2, same-age and same-sex dyads from two age groups (4- and 5-year-olds) were observed in experimental settings playing with blocks alone and with dramatic props alone. Both contexts elicited a predominance of imaginative language, though the dramatic context elicited more imaginative language than the blocks. With age, children generated more individual functions and multifunctional utterances.     

Acquisition of mental state language in Spanish children: a longitudinal study of the relationship between the production of mental verbs and linguistic development

The development of language indicating the emergence of thinking about the thoughts of self and others has been scarcely studied in Spanish-speaking children. For this reason, we studied the development of mental state language and various indicators of language development in 25 Spanish-speaking children assessed at 3, 3 1/2, 4, 4 1/2, and 5 years of age. We coded and categorized the 40,250 utterances children produced during the five time points, 1202 (3.01%) of which had mental terms. In this sample, mental state language in Spanish children developed with a similar timeline and patterns as described in English-speaking children. However, several findings were novel for studies of mental state language. The general indexes of syntactic development did not correlate with the production of mental terms. The Index of Lexical Diversity was associated with the frequency of references to verbs of desire. The results of regression analyses suggest that not only the development of subordinate sentences with complement is associated with genuine mental references to desires and beliefs, but the development of lexical skills as well.     

Isolated words enhance statistical language learning in infancy

Infants are adept at tracking statistical regularities to identify word boundaries in pause-free speech. However, researchers have questioned the relevance of statistical learning mechanisms to language acquisition, since previous studies have used simplified artificial languages that ignore the variability of real language input. The experiments reported here embraced a key dimension of variability in infant-directed speech. English-learning infants (8-10 months) listened briefly to natural Italian speech that contained either fluent speech only or a combination of fluent speech and single-word utterances. Listening times revealed successful learning of the statistical properties of target words only when words appeared both in fluent speech and in isolation; brief exposure to fluent speech alone was not sufficient to facilitate detection of the words' statistical properties. This investigation suggests that statistical learning mechanisms actually benefit from variability in utterance length, and provides the first evidence that isolated words and longer utterances act in concert to support infant word segmentation.     

Phonological Working Memory and Spoken Language Development in Young Children

This study investigated the relationship between phonological working memory and spoken language development in a large unselected sample of 4- and 5-year old children. Assessments were made of the language produced by the children on the Bus Story (Renfrew, 1969), a standard test of continuous speech. In this test, children listen to a story, which they then recount with the aid of visual clues. The amount of information recalled and the average length of the five longest utterances are taken as indices of children's expressive language abilities. Phonological working memory skills were indexed by memory span and the ability to repeat non-words. The ability to repeat non-words made a significant contribution to the variance in the children's speech independently of age, vocabulary knowledge, and nonverbal cognitive skills. The possible mechanisms by which skills assessed by phonological memory tasks may be linked to the development of speech production abilities are considered.     

Perceived variability and symbol use: a common language-cognition interface in children and chimpanzees (Pan troglodytes)

Analysis of two chimpanzees' conversations with their teacher during a tool-use training task demonstrated that chimps use lexigrams, a humanly devised visual symbol system, selectively to encode perceived variability; that is, they generally used their symbols to differentiate alternative possibilities or to represent change or novelty in a situation. In contrast, they tended to leave unsaid what was unchanging, repetitive, or the unique possibility in a situation. Perceived variability influenced not only which symbols were selected but also utterance length: A single dimension of variability in a situation leads to single-lexigram utterances; multiple dimensions are associated with multi-lexigram utterances. This pattern of results indicates that the absence of formal grammatical structure in chimp language does not imply that utterances beyond one word in length are either rote strings or imitations. The chimps' tendency to mention the variable while leaving the constant or redundant unsaid is, moreover, strong support for the position that their use of a humanly devised symbol system is more than a series of conditioned responses.     

Inter- and intra-individual variability in the kinematics of the back squat

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (V_Barbell) and angular velocity of the ankle (ω_Ankle), knee (ω_Knee) and hip joint (ω_Hip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in V_Barbell, ω_Ankle, ω_Knee, and ω_Hip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.     

Recasts in parents' language to their school-age children who stutter: a preliminary study

Language samples collected from 13 school-age children diagnosed as stutterers (CWS) in conversation with a parent and a similar corpus of data collected from a matched control group of 13 normally-fluent children (CWNS) were analyzed for the quality and quantity of recast usage in the parents' language. Recasts, a frequently studied type of child-directed language (CDL) pattern hypothesized to increase the length and complexity of young children's expressive language, have not been studied typically in older children's conversations with parents nor have they been studied in the CDL of parents of CWS. Comparisons of these samples revealed that both groups of parents were frequent users of imitations, as well as simple and complex type recasts. Indeed, the rank order of recast types used was identical for the two groups of caregivers. When parents' conversations with the CWS were analyzed further, it was noted that they were not more likely to focus on stuttered utterances as the utterances on which to base their recasts (i.e., "platform utterances") than on the child's fluently-produced utterances. These results suggest there is one additional conversation parameter for which there are evident similarities in the CDL used by parents of CWS and CWNS. Clinical implications gleaned from this preliminary study are discussed, as are suggestions for future study. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to describe (1) the role of recasts in young children's language development; (2) the types of recasts that were observed in the conversations of parents of CWS and CWNS; and (3) the similarities observed in the recasts produced by parents of CWS and CWNS.     

Selected pragmatic features in Spanish-speaking preschool children

We assessed Spanish-speaking preschool children for the development of seven language functions and three discourse features. Analyses consisted of spontaneous language samples averaging 136 utterances per child, for 18 subjects between 3:0 and 4:5 (years: months). Data for the frequency of occurrence and the percentage of appropriate usage showed that the preschoolers had established communicative competence for the functions and discourse features. Implications include establishing preliminary guidelines for the development of normal pragmatics in Hispanic preschoolers. We also discuss the 10-item taxonomy as a reliable and clinically useful tool with either English-speaking or Spanish-speaking children.     

Audience Design in Multiparty Conversation

How do speakers design what they say in order to communicate effectively with groups of addressees who vary in their background knowledge of the topic at hand? Prior findings indicate that when a speaker addresses a pair of listeners with discrepant knowledge, that speakers Aim Low, designing their utterances for the least knowledgeable of the two addressees. Here, we test the hypothesis that speakers will depart from an Aim Low approach in order to efficiently communicate with larger groups of interacting partners. Further, we ask whether the cognitive demands of tracking multiple conversational partners' perspectives places limitations on successful audience design. We find that speakers can successfully track information about what up to four of their partners do and do not know in conversation. When addressing groups of 3–4 addressees at once, speakers design language based on the combined knowledge of the group. These findings point to an audience design process that simultaneously represents the perspectives of multiple other individuals and combines these representations in order to design utterances that strike a balance between the different needs of the individuals within the group.     

Effects of warned and unwarned demand transitions on vigilance performance and stress

The present study was designed to explore the effects of warned and unwarned demand transitions in vigilance on performance and self-reported stress. Twenty observers (10 women and 10 men) were assigned at random to each of six conditions resulting from the factorial combination of signal salience (high and low salience signals) and switching (no switch, switch with warning, and switch without warning). Performance metrics and self-reported stress state (Task Engagement, Distress, and Worry) were collected. While demand transitions did destabilize subsequent performance, increasing intra-individual variability, overall performance efficiency was uninfluenced by either switching or warning. Demand transitions, whether warned or not, increased self-reported distress. A dynamic model of performance stress may be necessary and research employing vigilance tasks in the future may be useful for developing this performance-stress model.     

Starting over: international adoption as a natural experiment in language development

Language development is characterized by predictable shifts in the words children produce and the complexity of their utterances. Because acquisition typically occurs simultaneously with maturation and cognitive development, it is difficult to determine the causes of these shifts. We explored how acquisition proceeds in the absence of possible cognitive or maturational roadblocks, by examining the acquisition of English in internationally adopted preschoolers. Like infants, and unlike other second-language learners, these children acquire language from child-directed speech, without access to bilingual informants. Parental reports and speech samples were collected from 27 preschoolers, 3 to 18 months after they were adopted from China. These children showed the same developmental patterns in language production as monolingual infants (matched for vocabulary size). Early on, their vocabularies were dominated by nouns, their utterances were short, and grammatical morphemes were generally omitted. Children at later stages had more diverse vocabularies and produced longer utterances with more grammatical morphemes.     

Gesture Reflects Language Development: Evidence From Bilingual Children

There is a growing awareness that language and gesture are deeply intertwined in the spontaneous expression of adults. Although some research suggests that children use gesture independently of speech, there is scant research on how language and gesture develop in children older than 2 years. We report here on a longitudinal investigation of the relation between gesture and language development in French-English bilingual children from 2 to 3 1/2 years old. The specific gesture types of iconics and beats correlated with the development of the children's two languages, whereas pointing types of gestures generally did not. The onset of iconic and beat gestures coincided with the onset of sentencelike utterances separately in each of the children's two languages. The findings show that gesture is related to language development rather than being independent from it. Contrasting theories about how gesture is related to language development are discussed.     

Reasons for the growth of traditional memory span across age

Three studies, covering together the age range from 3 to 16 years, show the relationships between age, short-term memory span, and language abilities. The growth of the traditional memory span in childhood is systematically related to a concomitant growth of language abilities as tested with CELF-3 Screening, two tests of word knowledge, a test of reception of grammar (TROG-2), and the British Picture Vocabulary Test (BPVS). Linear regression and ANCOVA analyses show that the growth of memory span is fully explained by the growth of language abilities in the three studies that covered different subsamples of children. In a confirmatory factor analysis a two-factor model fits the data well and shows that a “crystallised” language factor is strongly related to age, whereas a “fluid” short-term memory factor is unrelated to age. The two-factor model gives support to Baddeley's multicomponent model of working memory, and the current data suggest that the capacity of the phonological store is fully developed in children younger than 4 years old. The authors hold that chunking capacity, highly dependent on language abilities, is a major source of memory span growth with age. Rather than an increase in the number of chunks, or episodes retained in short-term memory (=chunk span), it is argued that childhood memory span development reflects an increase in the size of each chunk (=chunking capacity).     

Spontaneous analogical transfer in 4-year-olds: a microgenetic study

The purpose of the current microgenetic study was to examine children's spontaneous application of analogical problem solving from story problems to physical tasks. Thirty-six 4-year-olds (M=54.7 months), randomly assigned to an experimental or a control condition, participated. The results indicate that 4-year-old children did, with varying success, spontaneously apply analogical solutions to physical problems across sessions. A positive effect over time on children's spontaneous analogical problem solving was found. Additionally, a few children even gave an analogical strategy-related explanation for their own physical behavior. There was much inter- and intra-individual variability, which may indicate that 4 years of age is a period of change in the development of analogical reasoning.     

The role of speech rhythm in language discrimination: further tests with a non-human primate

Human newborns discriminate languages from different rhythmic classes, fail to discriminate languages from the same rhythmic class, and fail to discriminate languages when the utterances are played backwards. Recent evidence showing that cotton-top tamarins discriminate Dutch from Japanese, but not when utterances are played backwards, is compatible with the hypothesis that rhythm discrimination is based on a general perceptual mechanism inherited from a primate ancestor. The present study further explores the rhythm hypothesis for language discrimination by testing languages from the same and different rhythmic class. We find that tamarins discriminate Polish from Japanese (different rhythmic classes), fail to discriminate English and Dutch (same rhythmic class), and fail to discriminate backwards utterances from different and same rhythmic classes. These results provide further evidence that language discrimination in tamarins is facilitated by rhythmic differences between languages, and suggest that, in humans, this mechanism is unlikely to have evolved specifically for language.     

Direct and Indirect Effects of Behavioral Parent Training on Infant Language Production

Given the strong association between early behavior problems and language impairment, we examined the effect of a brief home-based adaptation of Parent–child Interaction Therapy on infant language production. Sixty infants (55% male; mean age 13.47 ± 1.31 months) were recruited at a large urban primary care clinic and were included if their scores exceeded the 75th percentile on a brief screener of early behavior problems. Families were randomly assigned to receive the home-based parenting intervention or standard pediatric primary care. The observed number of infant total (i.e., token) and different (i.e., type) utterances spoken during an observation of an infant-led play and a parent-report measure of infant externalizing behavior problems were examined at pre- and post-intervention and at 3- and 6-month follow-ups. Infants receiving the intervention demonstrated a significantly higher number of observed different and total utterances at the 6-month follow-up compared to infants in standard care. Furthermore, there was an indirect effect of the intervention on infant language production, such that the intervention led to decreases in infant externalizing behavior problems from pre- to post-intervention, which, in turn, led to increases in infant different utterances at the 3- and 6-month follow-ups and total utterances at the 6-month follow-up. Results provide initial evidence for the effect of this brief and home-based intervention on infant language production, including the indirect effect of the intervention on infant language through improvements in infant behavior, highlighting the importance of targeting behavior problems in early intervention.     

The Power to Detect and Predict Individual Differences in Intra-Individual Variability Using the Mixed-Effects Location-Scale Model

Our goal is to provide empirical scientists with practical tools and advice with which to test hypotheses related to individual differences in intra-individual variability using the mixed-effects location-scale model. To that end, we evaluate Type I error rates and power to detect and predict individual differences in intra-individual variability using this model and provide empirically-based guidelines for building scale models that include random and/or systematically-varying fixed effects. We also provide two power simulation programs that allow researchers to conduct a priori empirical power analyses. Our results aligned with statistical power theory, in that, greater power was observed for designs with more individuals, more repeated occasions, greater proportions of variance available to be explained, and larger effect sizes. In addition, our results indicated that Type I error rates were acceptable in situations when individual differences in intra-individual variability were not initially detectable as well as when the scale-model individual-level predictor explained all initially detectable individual differences in intra-individual variability. We conclude our paper by providing study design and model building advice for those interested in using the mixed-effects location-scale model in practice.     

Intra-Individual Variability of Normal and Educable Mentally Retarded Children on a Coincidence Timing Task

A visual coincidence timing task was used to compare the level of performance (constant error) and the intra-individual variability of 100 normal and 100 educable mentally retarded children. The mean performance of the intellectually normal children on this task was significantly superior to that of the retarded children, and the intra-individual variability of the latter was significantly greater than that of the former. The hypothesis that high intra-individual variability and depressed level of performance are closely associated was not supported.