Stephanie F. Stokes

What's in a Word? Morphological Awareness and Vocabulary Knowledge in Three Languages.

Understanding how words are created is potentially a key component to being able to learn and understand new vocabulary words. However, research on morphological awareness is relatively rare. In this study, over 660 preschool-aged children from three language groups (Cantonese, Mandarin, and Korean speakers) in which compounding morphology is highly prevalent were tested on their abilities to manipulate familiar morphemes to create novel compound words as well as on a variety of early language and reasoning measures twice over the span of 9 months to 1 year. With Time 1 vocabulary knowledge, phonological processing, and reasoning skills controlled, morphological awareness predicted unique variance in Time 2 vocabulary knowledge across languages. Across languages, vocabulary knowledge also predicted unique variance in subsequent morphological awareness, with Time 1 morphological awareness controlled. Findings underscore the bidirectional bootstrapping of morphological awareness and vocabulary acquisition for languages in which lexical compounding is prominent, and suggest that morphological awareness may be practically important in predicting and fostering childrens early vocabulary learning.

Factors that influence vocabulary development in two-year-old children

BACKGROUND This research explored the relative impact of demographic, cognitive, behavioural, and psycholinguistic factors on vocabulary development in two-year-old children. METHODS Two hundred and thirty-two children (24-30 months) were tested on expressive and receptive vocabulary, cognitive development, word learning and working memory skills. Parents completed a British adaptation (Klee & Harrison, 2001) of the MacArthur-Bates Communicative Development Inventory (CDI; Fenson et al., 1993), a demographic questionnaire and a questionnaire regarding the childs social-emotional behaviour. RESULTS Several demographic, child and processing variables were significantly correlated with CDI (vocabulary) scores, but the only significant unique predictors of CDI scores were nonword repetition (NWR; R(2) change = .36), sex (R(2) change = .05) and age (R(2) change = .04). Scores were only included when a child completed the entire NWR test (77% of toddlers). CONCLUSIONS The NWR task used in this experiment maximised participation in this group of toddlers, and was a strong predictor of vocabulary ability. Longitudinal research is warranted to explore the independent and reciprocal growth in working memory and language skills in children.

Electropalatography Treatment in an Adult with Late Repair of Cleft Palate

This paper describes the use of electropalatography (EPG) in the treatment of a speech disorder in a Cantonese-speaking woman who had primary repair of the palate at age 13. A multiple-baseline approach was used to document treatment efficacy using electropalatography. The client showed rapid improvement in articulatory placement, with generalization to nontarget phonemes. In addition, improvement was noted in her manner of articulation, with a reduction of nasal emission. The relationship between articulatory placement errors and nasal emission in late repair cleft is discussed. Explanations for the effectiveness of EPG with this client are offered.

The Production of Passives by Children with Specific Language Impairment Acquiring English or Cantonese.

The production of passive sentences by children with specific language impairment (SLI) was studied in two languages, English and Cantonese. In both languages, the word order required for passive sentences differs from the word order used for active sentences. However, English and Cantonese passive sentences are quite different in other respects. We found that English-speaking children with SLI were less proficient than both same-age and younger typically developing peers in the use of passives, though difficulty could not be attributed to word order or a reliance on active sentences. Cantonese-speaking children with SLI proved less capable than same-age peers but at least as proficient as younger peers in their use of passive sentences. The implications of these cross-linguistic differences are discussed.

Extended Statistical Learning as an account for slow vocabulary growth

Stokes (2010) compared the lexicons of English-speaking late talkers (LT) with those of their typically developing (TD) peers on neighborhood density (ND) and word frequency (WF) characteristics and suggested that LTs employed learning strategies that differed from those of their TD peers. This research sought to explore the cross-linguistic validity of this conclusion. The lexicons (production, not recognition) of 208 French-speaking two-year-old children were coded for ND and WF. Regression revealed that ND and WF together predicted 62% of the variance in vocabulary size, with ND and WF uniquely accounting for 53% and 9% of that variance respectively. Epiphenomenal findings were ruled out by comparison of simulated data sets with the actual data. A generalized Mann-Whitney test showed that children with small vocabularies had significantly higher ND values and significantly lower WF values than children with large vocabularies. An EXTENDED STATISTICAL LEARNING theory is proposed to account for the findings.

Early Language Delay and Specific Language Impairment

Early language delay (ELD) is a warning sign that may presage the presence of a later language impairment (LI). In order to allow more targeted identification and earlier intervention for LI, better diagnostic measures for toddlers are needed. Development of accurate predictive/diagnostic models requires consideration of a set of complex interrelated questions around definition, causality, and theories of LIs. A multifactorial model of language development and LI is essential to increase the accuracy of prediction. This article examines what is known about LI in the preschool years and language delay in toddlers, and examines these in relation to the Procedural Deficit Hypothesis (Ullman and Pierpont, [2005] Cortex 41:399-433] and the Statistical Learning Account (Stokes et al., [2012a] J Speech Lang Hear Res; Stokes et al., [2012b] J Child Lang 39:105-129) to suggest a new framework for characterizing ELD to better assist prediction of later LI.

Early Oral Language Markers of Poor Reading Performance in Hong Kong Chinese Children

This study investigated the extent to which language skills at ages 2 to 4 years could discriminate Hong Kong Chinese poor from adequate readers at age 7. Selected were 41 poor readers (age M = 87.6 months) and 41 adequate readers (age M = 88.3 months). The two groups were matched on age, parents’ education levels, and nonverbal intelligence. The following language tasks were tested at different ages: vocabulary checklist and Cantonese articulation test at age 2; nonword repetition, Cantonese articulation, and receptive grammar at age 3; and nonword repetition, receptive grammar, sentence imitation, and story comprehension at age 4. Significant differences between the poor and adequate readers were found in the age 2 vocabulary knowledge, age 3 Cantonese articulation, and age 4 receptive grammar skill, sentence imitation, and story comprehension. Among these measures, sentence imitation showed the greatest power in discriminating poor and adequate readers.

Vowel and diphthong development in Cantonese-speaking children

Spontaneous speech samples were collected from 40 Cantonese-speaking children aged between 10 and 27 months. Over 7, 000 vowels and diphthongs were transcribed and analysed to determine the accuracy of production of Cantonese vowels and diphthongs. A model of feature complexity was derived from the distinctive features of vowels to predict the route of development of vowels and diphthongs. Two factors were found to affect development: a linguistic factor (frequency of occurrence in the ambient language) and an articulatory factor (feature complexity). Early dependence on the feature complexity of segments at 15-18 months is superseded by ambient language influences by 24 months of age.

Modal verbs with and without tense: a study of English- and Cantonese-speaking children with specific language impairment.

BACKGROUND Surprisingly little is known about the use of modal auxiliaries by children with specific language impairment (SLI). These forms fall within the category of grammatical morphology, an area of morphosyntax that is purportedly very weak in children with SLI. AIMS Three studies were conducted to examine the use of modal auxiliaries by preschool-aged children with SLI. METHODS & PROCEDURES In each study, probe tasks were designed to create contexts that encouraged the use of modals to express the modality functions of ability and permission. In Studies 1 and 3, English-speaking children participated. In Study 2, the participants were Cantonese-speaking children. In each study, three groups of children participated: A group exhibiting SLI, a group of younger typically developing children (YTD), and a group of (older) typically developing children (OTD) matched with the SLI group according to age. OUTCOME & RESULTS In Study 1, English-speaking children with SLI were as proficient as YTD children, though less proficient than OTD children in the use of the modal can to express the modality functions of ability and permission. In Study 2, the same modality functions were studied in the speech of SLI, YTD and OTD groups who were speakers of Cantonese. In this language, tense is not employed, and therefore the modality function could be examined independent of formal tense. Results similar to those of Study 1 were obtained. Study 3 again studied SLI, YTD and OTD groups in English to determine whether the childrens expression of ability differed across past (could) and non-past (can) contexts. The results for can replicated the findings from Study 1. However, the children with SLI were significantly more limited than both the YTD and OTD groups in their use of could. CONCLUSIONS The results suggest that most children with SLI have access to modality functions such as ability and permission. However, the findings of Study 3 suggest that they may have a reduced inventory of modal forms or difficulty expressing the same function in both past and non-past contexts. These potential areas of difficulty suggest possible directions for intervention.

EPG treatment of sibilants in two Cantonese-speaking children with cleft palate

Two Cantonese-speaking children with cleft palate participated in an EPG treatment programme focused on sibilants. Remediation was rapid, and systemic changes occurred as a result of generalization. Implications for the description of the nature of affricates, their developmental route and the difficulty they pose for children with speech disorders are addressed. The findings are discussed within a model of output constraints according to a theory of phonological neighbourhood complexity.