Convergence and divergence in prediction from vocabulary and speed of word processing.

Toddler vocabulary knowledge and speed of word processing are associated with downstream language and cognition. Here, we investigate whether these associations differ across measures. At age two, 101 participants (55 monolingual French-speaking and 46 monolingual English-speaking children) completed a two-alternative forced choice task, yielding measures of decontextualized vocabulary (number of correct responses) and haptic speed of word processing (latency of correct responses). At ages three, four, and five children completed a battery of language assessments and an executive function task. Growth curve models revealed that age-two vocabulary significantly predicted age-three performance (but not growth from age three to four or four to five) across all language assessments but speed of processing did not predict language outcomes in final models. Finally, speed of processing was correlated with executive function at age three whereas vocabulary was not. Results suggest that vocabulary is associated with a range of downstream language abilities whereas haptic speed of processing may be associated with executive control.

The Relationship Between Lexical and Phonological Development in French-Speaking Children: A Longitudinal Study.

Purpose This study examines the influence of lexical and phonological factors on expressive lexicon size in 40 French-speaking children tested longitudinally from 22 to 48 months. The factors include those based on the lexical and phonological properties of words in the children's lexicons (phonetic complexity, word length, neighborhood density [ND], and word frequency [WF]) as well as variables measuring phonological production (percent consonants correct and phonetic inventory size). Specifically, we investigate the relative influence of these factors at individual ages, namely, 22, 29, 36, and 48 months, and which factors measured at 22 and 29 months influence lexicon size at 36 and 48 months. Method Children were selected based on parent-reported vocabulary size. We included children with low, medium, and high vocabulary scores. The children's lexicons were coded in terms of phonetic complexity, word length, ND, and WF, and their phonological production skills were based on measures of percent consonants correct and phonetic inventory size extracted from spontaneous speech samples at 29, 36, and 48 months. In the case of ND and WF, we focused on one- and two-syllable nouns. Results Across the age range, the most important factor that explained variance in lexicon size was the WF of nouns. Children who selected low-frequency nouns had larger vocabularies across all ages (22-48 months). The WF of two-syllable nouns and phonological production measured at 29 months influenced lexicon size at 36 months, whereas the WF (of one- and two-syllable words) influenced lexicon size at 48 months. Conclusions The findings support the role of WF and phonological production in explaining expressive vocabulary development. Children enlarge their vocabularies by adding nouns of increasingly lower frequency. Phonological production plays a role in accounting for vocabulary size up until the age of 36 months. Supplemental Material https://doi.org/10.23641/asha.12291074.

Do early lexical skills predict language outcome at 3 years? A longitudinal study of French-speaking children.

Early language development is considered critical for children's adjustment in school, for social adaptation and for later educational achievement. Despite the role of children's receptive skills as a foundation for later productive word use, receptive language skills have received surprisingly little attention. The present research extends recent work on the prediction of preschool language skills by exploring whether a decontextualized measure of lexical comprehension can account for unique variance in preschool language skills above and beyond parent report and how early such a prediction can be made. For this purpose, 65 French-speaking children have been tested at 16, 22, 29 and 36 months. The results of the current study suggest that up to the age of two, although parent reports of lexical comprehension and/or production account for a portion of variance in later receptive, productive or general language outcome, they have less predictive validity than a direct measure of early lexical comprehension. By contrast, after age two, parent reported vocabulary production is the strongest predictor of later language production skills.

Language status at age 3: Group and individual prediction from vocabulary comprehension in the second year.

The present research extends recent work on the prediction of preschool language skills by exploring prediction from decontextualized vocabulary comprehension. Vocabulary comprehension was a stronger predictor than parent-reported production, yielding a quadrupling of variance accounted for relative to prior studies. Parallel studies (Studies 1 and 2) are reported for two linguistically and geographically distinct samples. In both samples, decontextualized vocabulary comprehension late in the second year provided the best balance between model fit and parsimony in predicting language skills at age three. In Study 3, vocabulary comprehension prospectively identified children with low language status 2 years earlier than other prospective studies but with similar sensitivity and specificity. The present paper provides evidence on three questions of practical and theoretical significance: the relation between decontextualized vocabulary prior to 30 months of age and language outcomes, how prediction from decontextualized vocabulary compares with parent-reported vocabulary, and finally how early stable predictions to language outcomes can be made. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The relation between phonological and lexical development in French-speaking children.

This study examines the relation between lexical and phonological variables in 40 French-speaking children, aged 2;5. Specifically, it examines the influence of phonetic complexity, phonological production, phonological memory and neighbourhood density (ND) on vocabulary size. Children were divided into four groups on the basis of their scores on the French version of the Communicative Developmental Inventory (CDI): late1 (< 10%ile), late2 (15-25%ile), middle (40-60%ile) and precocious (> 90%ile). The children's lexicons were coded in terms of phonetic complexity and ND (one-and two-syllable words), and their production capacities were determined from measuring percent consonants correct (PCC) and the number of syllable-initial (CSI) and -final (CSF) consonants in their phonetic inventories. The children also took part in a non-word repetition (NWR) task. Results indicated significant group differences in all four sets of variables. Children with larger vocabularies selected words with greater phonetic complexity and with lower ND values. They had superior PCC, CSI and NWR scores compared to children with smaller vocabularies. Linear regression analyses indicated that 76% of variance in vocabulary size could be accounted for by ND in combination with phonetic complexity and CSI. Our findings are consistent with previous studies which show that ND plays an important role in accounting for variance in vocabulary size. They also indicate that phonetic complexity and phonological production influence lexical acquisition.