Donna J. Thal

Variability in Early Communicative Development.

Data from parent reports on 1,803 children--derived from a normative study of the MacArthur Communicative Development Inventories (CDIs)--are used to describe the typical course and the extent of variability in major features of communicative development between 8 and 30 months of age. The two instruments, one designed for 8-16-month-old infants, the other for 16-30-month-old toddlers, are both reliable and valid, confirming the value of parent reports that are based on contemporary behavior and a recognition format. Growth trends are described for children scoring at the 10th-, 25th-, 50th-, 75th-, and 90th-percentile levels on receptive and expressive vocabulary, actions and gestures, and a number of aspects of morphology and syntax. Extensive variability exists in the rate of lexical, gestural, and grammatical development. The wide variability across children in the time of onset and course of acquisition of these skills challenges the meaningfulness of the concept of the modal child. At the same time, moderate to high intercorrelations are found among the different skills both concurrently and predictively (across a 6-month period). Sex differences consistently favor females; however, these are very small, typically accounting for 1%-2% of the variance. The effects of SES and birth order are even smaller within this age range. The inventories offer objective criteria for defining typicality and exceptionality, and their cost effectiveness facilitates the aggregation of large data sets needed to address many issues of contemporary theoretical interest. The present data also offer unusually detailed information on the course of development of individual lexical, gestural, and grammatical items and features. Adaptations of the CDIs to other languages have opened new possibilities for cross-linguistic explorations of sequence, rate, and variability of communicative development.

Spoken Language Development in Children Following Cochlear Implantation

CONTEXT Cochlear implantation is a surgical alternative to traditional amplification (hearing aids) that can facilitate spoken language development in young children with severe to profound sensorineural hearing loss (SNHL). OBJECTIVE To prospectively assess spoken language acquisition following cochlear implantation in young children. DESIGN, SETTING, AND PARTICIPANTS Prospective, longitudinal, and multidimensional assessment of spoken language development over a 3-year period in children who underwent cochlear implantation before 5 years of age (n = 188) from 6 US centers and hearing children of similar ages (n = 97) from 2 preschools recruited between November 2002 and December 2004. Follow-up completed between November 2005 and May 2008. MAIN OUTCOME MEASURES Performance on measures of spoken language comprehension and expression (Reynell Developmental Language Scales). RESULTS Children undergoing cochlear implantation showed greater improvement in spoken language performance (10.4; 95% confidence interval [CI], 9.6-11.2 points per year in comprehension; 8.4; 95% CI, 7.8-9.0 in expression) than would be predicted by their preimplantation baseline scores (5.4; 95% CI, 4.1-6.7, comprehension; 5.8; 95% CI, 4.6-7.0, expression), although mean scores were not restored to age-appropriate levels after 3 years. Younger age at cochlear implantation was associated with significantly steeper rate increases in comprehension (1.1; 95% CI, 0.5-1.7 points per year younger) and expression (1.0; 95% CI, 0.6-1.5 points per year younger). Similarly, each 1-year shorter history of hearing deficit was associated with steeper rate increases in comprehension (0.8; 95% CI, 0.2-1.2 points per year shorter) and expression (0.6; 95% CI, 0.2-1.0 points per year shorter). In multivariable analyses, greater residual hearing prior to cochlear implantation, higher ratings of parent-child interactions, and higher socioeconomic status were associated with greater rates of improvement in comprehension and expression. CONCLUSION The use of cochlear implants in young children was associated with better spoken language learning than would be predicted from their preimplantation scores.

EARLY LEXICAL DEVELOPMENT IN CHILDREN WITH FOCAL BRAIN INJURY

Early lexical development in 27 children with focal brain injury was studied cross-sectionally and longitudinally. Data were obtained from children between 12 and 35 months of age who acquired their lesion prenatally or within the first 6 months of life. Results for the group as a whole provide clear evidence for delays in lexical comprehension and production, and for a larger number of comprehension/production dissociations than would be expected by chance. In addition, a significant number of children were observed having unusual difficulty mastering predication and/or using an atypically high proportion of closed class words (suggesting reliance on holistic/formulaic speech). Analyses by lesion type revealed no effect of lesion size. Analyses according to side of lesion revealed that children with right-hemisphere damage produced a higher proportion of closed class words, suggesting heavy reliance on well-practiced but under-analyzed speech formulae. Children with left-hemisphere damage were slightly better in comprehension than children with right-hemisphere damage. In addition, left posterior lesions were associated with greater delays in expressive language, and delays were more protracted in children with left posterior damage. No differential effects of left posterior damage were found for lexical comprehension.

Early Lexical Development in Spanish-Speaking Infants and Toddlers.

This paper describes the early lexical development of a group of 328 normal Spanish-speaking children aged 0;8 to 2;7. First the development and structure of a new parent report instrument, Inventario del Desarollo de Habilidades Communicativas is described. Then five studies carried out with the instrument are presented. In the first study vocabulary development of Spanish-speaking infants and toddlers is compared to that of English-speaking infants and toddlers. The English data were gathered using a comparable parental report, the MacArthur Communicative Development Inventories. In the second study the general characteristics of Spanish language acquisition, and the effects of various demographic factors on that process, are examined. Study 3 examines the differential effects of three methods of collecting the data (mail-in, personal interview, and clinic waiting room administration). Studies 4 and 5 document the reliability and validity of the instrument. Results show that the trajectories of development are very similar for Spanish- and English-speaking children in this age range, that children from varying social groups develop similarly, and that mail-in and personal interview administration techniques produce comparable results. Inventories administered in a medical clinic waiting room, on the other hand, produced lower estimates of toddler vocabulary than the other two models.

From first words to grammar in children with focal brain injury

The effects of focal brain injury were investigated in the first stages of language development, during the passage from first words to grammar. Parent report, free‐speech data, or both are reported for 53 infants and preschool children between 10 and 44 months of age. All children had suffered a single, unilateral brain injury to the left or right hemisphere, incurred before 6 months of age (usually in the pre‐ or perinatal period). This is the period in which one would expect to see maximal plasticity, but it is also the period in which the initial specializations of particular cortical regions ought to be most evident. In direct contradiction of hypotheses based on the adult aphasia literature, results from 10 to 17 months suggest that children with right‐hemisphere injuries are at greater risk for delays in word comprehension and in the gestures that normally precede and accompany language onset. Although there were no differences between left‐ and right‐hemisphere injury per se on expressive language...

Measuring Variability in Early Child Language: Don't Shoot the Messenger

Feldman et al. criticize the MacArthur Communicative Development Inventories (CDIs) as having too much variability, too little stability, and insufficient ability to predict early language delay. We present data showing that these characteristics of the CDI are authentic reflections of individual differences in early language development rather than measurement deficiencies. We also respond to their critical assertions concerning sociodemographic influences on the CDI scores.

Integrating Language and Gesture in Infancy

Whether language/gesture correlations in early language development can be explained by parallelism or comprehension mediation was examined. Study 1, parental report data for 95 l-year-olds, suggested that word comprehension and production are dissociated in this age range and that the comprehension and production factors map onto distinct aspects of gesture. Study 2 tested 41 13-15month-olds in a task in which the modeled gesture was accompanied by supportive, contradictory, or neutral narratives. Results showed that infants can use adult speech as an aid in reproduction of modeled gestures (comprehension mediation). However, there is still additional variance in gestural production that correlates with expressive vocabulary when comprehension-related variance is removed. Thus, comprehension mediation and parallelism both appear to be operating.

Continuity of language abilities: An exploratory study of late‐ and early‐talking toddlers

Three exploratory studies were carried out to determine if there was continuity in the development of language in young children at the upper and lower extremes of the normal continuum, and if it was possible to use variables from an early assessment to predict their language status at a later date. Studies 1 and 2 examined continuity over 6‐month periods (from approximately 20 to 26 months and 13 to 20 months of age, respectively); Study 3 examined continuity from 8 to 30 months of age. Results provided solid evidence for continuity at the group level but no evidence of an ability to predict outcome for individual children using the vocabulary production, vocabulary comprehension, and gesture production variables included in this study.

Influence Of Implantation Age On School-Age Language Performance In Pediatric Cochlear Implant Users

Abstract Objective: This study examined specific spoken language abilities of 160 children with severe-to-profound sensorineural hearing loss followed prospectively 4, 5, or 6 years after cochlear implantation. Study sample: Ninety-eight children received implants before 2.5 years, and 62 children received implants between 2.5 and 5 years of age. Design: Language was assessed using four subtests of the Comprehensive Assessment of Spoken Language (CASL). Standard scores were evaluated by contrasting age of implantation and follow-up test time. Results: Children implanted under 2.5 years of age achieved higher standard scores than children with older ages of implantation for expressive vocabulary, expressive syntax, and pragmatic judgments. However, in both groups, some children performed more than two standard deviations below the standardization group mean, while some scored at or well above the mean. Conclusions: Younger ages of implantation are associated with higher levels of performance, while later ages of implantation are associated with higher probabilities of continued language delays, particularly within subdomains of grammar and pragmatics. Longitudinal data from this cohort study demonstrate that after 6 years of implant experience, there is large variability in language outcomes associated with modifiers of rates of language learning that differ as children with implants age.

Phonological and Lexical Development in Normal and Late-Talking Toddlers.

Toddlers in the lowest tenth percentile for lexical production, based on parental report (late talkers), were compared with age- and language-matched controls on measures of phonetic complexity, lexical development, and grammatical complexity. Late talkers were placed in the pre-meaningful speech group if they produced fewer than 10 different words or in the meaningful speech group if they produced more than 10 different words in a spontaneous language sample. Late talkers who had entered the meaningful speech stage scored higher than those who had not on most of the measures of phonology, lexical, and grammatical complexity in intelligible speech, but not on measures of phonological development in babble. These results are compatible with other studies that found an overlap between phonology, lexicon, and grammar, as well as with those that suggested the importance of true consonant production for lexical development.