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.

Ties between the lexicon and grammar: cross-sectional and longitudinal studies of bilingual toddlers.

Studies using the English and Spanish MacArthur Communicative Development Inventories demonstrated that the grammatical abilities of 20-30-month-old bilingual children were related more strongly to same-language vocabulary development than to broader lexical-conceptual development or maturation. First, proportions of different word types in each language varied with same-language vocabulary size. Second, individual changes in predicate and closed class word proportion scores were linked to growth in same-language vocabulary but not to total conceptual vocabulary. Third, increases in English utterance length and English and Spanish sentence complexity were related to growth in same-language vocabulary but not to growth in conceptual vocabulary. Increases in Spanish utterance length were linked to growth in both Spanish vocabulary and conceptual vocabulary. Possible mechanisms underlying these patterns are considered.

Nonword repetition and language development in 4-year-old children with and without a history of early language delay.

PURPOSE: This study examined the usefulness of the Nonword Repetition Test (NRT; C. Dollaghan & T. F. Campbell, 1998) with 4-year-old children and the relationship among the NRT, language, and other aspects of mental processing. METHOD: The NRT was administered to 64 children at 4 years of age; 44 had a history of typical language development (HTD), and 20 had a history of language delay (HLD) at 16 months of age. Study 1 compared methods of scoring phoneme errors to determine whether the NRT was appropriate for this age group. Study 2 examined whether the NRT differentiated HTD from HLD. Study 3 examined the relations among scores on the NRT and standardized tests of language and mental processing. RESULTS: The NRT was found to be appropriate for 4-year-old children. Although all children had normal language abilities at the time of the study, the NRT (and several aspects of language and mental processing) differentiated between HTD and HLD. Relations among the NRT and other measures of language and mental processing were different from those previously reported, an unexpected finding that is inconsistent with traditional accounts of working memory and its relation to language development. Potential explanations are explored, and some directions for future research are suggested.

Language development in children at risk for language impairment: cross-population comparisons.

At 3 years of age the spontaneous language of 17 typically developing children was compared to two groups of toddlers who were at risk for language delay for very different reasons. One at-risk group, late talkers, appeared normal in all respects except for their delayed language. These 20 children scored at or below the fifteenth percentile for expressive vocabulary on the MacArthur Communicative Development Inventory (Fenson et al., 1993) when originally identified at 20-27 months of age and within the normal range on the Bayley Scales of Infant Development (Bayley, 1969). The other group, 21 children with unilateral focal brain injury, suffered localized damage to their brain prenatally, perinatally, or within the first 6 months of life. Results indicated that both of the at-risk groups were still significantly lower in vocabulary diversity and grammar at 3 years of age. There was also significantly greater variability in the at-risk groups than in the control groups, and in the children with focal brain injury than in the late talkers in both areas. The importance of language comprehension to development in this period was supported by two findings. First, children with focal brain injury had significantly lower scores than late talkers on the Index of Productive Syntax, a test of emerging grammar, and had been lower in comprehension on a standardized test of language comprehension a year earlier. Second, late talkers with delay in comprehension as well as production had significantly lower scores on IPSyn than those with normal comprehension, suggesting that they are at greater risk for continued delay. Qualitative analyses indicated that the at-risk groups produced the same kinds of errors, but that late talkers produced a substantially greater proportion of errors in obligatory contexts than did children with focal brain injury.

Categorization and Its Developmental Relation to Early Language.

Three studies examine the developmental relation between early linguistic and cognitive achievements. Studies 1 and 2 attempt to replicate previous findings of a strong temporal link between the ages at there is a sharp rise in new nominal productions and the appearance of 2-category grouping using a longitudinal design. Studies 1 and 2 differ principally in whether the same stimuli were employed each time the children's categorization was tested or whether different stimuli were employed. Study 3 compares the categorization performance of children identified as late talkers to age-matched and language-matched controls cross-sectionally. Our findings consistently show that children's ability to classify objects in a spatial of temporal order is independent of advances in productive vocabulary growth. These results suggest that although children's developing knowledge of object categories may underlie developments in categorization and naming such developments depend on other abilities as well Studyin the past experiences of the child and the particular context in which the behavior is exhibited may be a more meaningful approach to understanding changes in categorization and ultimately its relation to language.