Improving the clinical utility of preschool language sample analysis

点击翻译按钮获取中文摘要

Project Summary Late talking (LT; late emergence of expressive language skill) in the absence of obvious primary perceptual, cognitive or motor impairment, is a serious developmental condition that may lead to academic, social and vocational handicap. While a majority of LTs appear to recover, many do not “catch up” and predicting why outcomes differ has been elusive. This supplemental application seeks to use a subset of the data being analyzed by the parent grant to perform a variety of longitudinal analyses of speech and language growth in late talkers (LTs) compared with typically-developing (TD) peers. Its overarching aim is to detect skills prior to and at roughly 24 months of age that may predict which children recover from late onset of expressive language and which children will experience lasting expressive language impairment. Our approach includes tracking the following sets of skills/behaviors from 24 to ~ 60 months of age in a combined cohort of > 70 LTs (and their TD peers). Of the LT children, roughly one-third remained persistently delayed by kindergarten entry, while 2/3 recovered to within the TD range of achievement. We examine: 1) growth in phonological inventory and syllable structure development; 2) recast behaviors by parents and the children’s responses to such recasts; 3) growth in expressive vocabulary diversity using a recently re-validated measure of lexical development; 4) differences in expressive phrase structure development, as measured by the Index of Productive Syntax, as potential predictors of more favorable outcome from LT. We will also examine whether infant speech segmentation and statistical learning skills assessed before 12 months of age in an additional sub-corpus followed by the parent grant were predictive of recovery from LT. A final analysis will examine the relationship of nonword repetition (NWR) at 24 months of age to later expressive language skills. Factors that appear to influence outcome of LT will be incorporated into a statistical model that best captures individual risk for persistence and recovery. Results will enable better and earlier identification of children for whom more intensive and targeted intervention is warranted. Further, understanding which skills appear to predict recovery will enable more informed language intervention targets and methods.