Biomedical subjects

Stephanie F Stokes

Publications and source records attributed to Stephanie F Stokes.

11 recordsLinked to original sources

PubMed2006

Nonword repetition and sentence repetition as clinical markers of specific language impairment: the case of Cantonese.

PURPOSE: Recent research suggests that nonword repetition (NWR) and sentence repetition (SR) tasks can be used to discriminate between children with SLI and their typically developing age-matched (TDAM) and younger (TDY) peers. METHOD: Fourteen Cantonese-speaking children with SLI and 30 of their TDAM and TDY peers were compared on NWR and SR tasks. NWR of IN nonwords (CV combinations attested in the language) and OUT nonwords (CV combinations unattested in the language) were compared. SR performance was compared using 4 different scoring methods. RESULTS: The SLI group did not score significantly lower than the TDAM group on the test of NWR (overall results were TDAM = SLI > TDY). There were nonsignificant group differences on IN syllables but not on OUT syllables. The results do not suggest a limitation in phonological working memory in Cantonese-speaking children with SLI. The SR task discriminated between children and their TDAM peers but not between children with SLI and their TDY peers matched for mean length of utterance. CONCLUSIONS: SR but not NWR discriminates between children with SLI and their TDAM peers. Poorer NWR for English-speaking children with SLI might be attributable to weaker use of the redintegration strategy in word repetition. Further cross-linguistic investigations of processing strategies are required.

Analysis of Variance↗

PubMed2005

Articulatory complexity, ambient frequency, and functional load as predictors of consonant development in children.

The notion of a universal pattern of phonological development, rooted in basic physiological constraints, is controversial, with some researchers arguing for a strong environmental (ambient language) influence on phonological development or an interaction of both physiological constraints and ambient language effects. This research examines the relative value of articulatory complexity, ambient frequency, and functional load as predictors of consonant development in children. Three languages are investigated: Cantonese, American English, and Dutch. Regression analyses revealed that functional load accounted for 55% of the variance in age of emergence of consonants in 7 English-speaking children (8-25 months), while frequency of consonants in the ambient language accounted for 63% of the variance in age of emergence of consonants in 51 Cantonese-speaking children (15-30 months). Articulatory complexity accounted for 40% of the accuracy of production of consonants in 40 English-speaking children (25 months), and frequency accounted for 43% of the variance in accuracy of production of consonants in 5 Dutch-speaking children (24 months). Given cross-linguistic differences, further research is required.

Child Language↗

PubMed2005

The expression of aspect in Cantonese-speaking children with specific language impairment.

Previous studies of verb morphology in children with specific language impairment (SLI) have been limited in the main to tense and agreement morphemes. Cantonese, which, like other Chinese languages, has no grammatical tense, presents an opportunity to investigate potential difficulties for children with SLI in other areas of verb morphology, via scrutiny of elements of its aspectual system. The performance of 3 groups of children (n = 15 in each group)--preschoolers with SLI, typically developing same-age peers, and younger, typically developing peers--was compared in procedures designed to elicit aspect forms. The children with SLI were less likely to produce both perfective and imperfective aspect markers. It is suggested that reasons for these findings are to be found in the sparse morphology of Cantonese and in the nonobligatory nature of these forms.

Analysis of Variance↗

PubMed2005

A phonemic implicational feature hierarchy of phonological contrasts for English-speaking children.

Contrastive feature hierarchies have been developed and used for some time in depicting typical phonological development and in guiding therapy decisions. Previous descriptions of feature use have been based on independent analyses and usually phonetic inventories. However, recent trends in phonology include a relational analysis of phonemic inventories (D. Ingram & K. D. Ingram, 2001). The current investigation was a relational analysis of the phonemic inventories of 40 typically developing 2-year-old American-English-speaking children. Consonant inventories were derived from spontaneous speech samples using the Logical International Phonetics Programs computer software (D. K. Oller & R. E. Delgado, 1999). Cluster analysis was used to determine the grouping of contrastive features. Four levels emerged. Level I included [consonant], [sonorant], and [coronal], Level II included [voice], Level III included [anterior], [continuant], and [nasal], and Level IV included [lateral] and [strident]. Results suggested that the resulting 4-level phonemic feature hierarchy might be used to classify the phonological systems of children with phonological disorders.

Articulation Disorders↗

PubMed2004

Three measures of language production for Cantonese-speaking school-age children in a story-retelling task.

Little is known about language development in school-age children in Asian countries. This research reports on 3 measures of language development in 100 Cantonese-speaking children age 5 to 9 years. Word scores, structure scores, and the mean length of communication units (MLCU) were derived from a story-retelling task. The structure score was significantly different for all, except the 8- and 9-year-old groups. The word score and MLCU were significantly different in groups separated by 2 or more years of age. All 3 measures were strongly and significantly correlated with age. The structure score and word score accounted for 64% and 5% of the variance in age, respectively. The order of development of the 6 grammatical structures (e.g., subordinate clauses) included in this study is also reported.

Child↗

PubMed2004

Utterance length and lexical diversity in Cantonese-speaking children with and without specific language impairment.

Two studies of children's conversational language abilities are reported. In the first, mean length of utterance (MLU) and lexical diversity (D) were examined in a group of typically developing Cantonese-speaking children in Hong Kong. Regression analyses indicated a significant linear relationship between MLU and age (R = .44) and a significant curvilinear relationship between D and age (R = .73) in children age 27-68 months. MLU and D were moderately correlated with each other (r = .23); however, the two measures showed no statistical relationship when the effect of age was partialled out. In a second study, the utterances of Chinese children with specific language impairment (SLI) were found to be significantly shorter and less lexically diverse than typically developing children matched for age but similar to children matched for comprehension level. Discriminant analyses revealed that the combination of age, MLU, and D could be used to accurately differentiate children with SLI from both age-matched and language-matched children. Based on these findings, we hypothesize that these measures can be used jointly as a marker of SLI in Cantonese-speaking children.

Age Factors↗

PubMed2004

Questions without movement: A study of Cantonese-speaking children with and without specific language impairment.

English-speaking children with specific language impairment (SLI) appear to have special difficulty in the use of who-object questions (e.g., Who is the girl chasing?). It has been argued that problems related to grammatical movement may be responsible for this difficulty. However, it is also possible that the lower frequency of who-object questions relative to who-subject questions also plays a role. In this study, the use of who-object and who-subject questions by children with SLI who were acquiring Cantonese as their 1 st language was examined. In Cantonese, the surface form of who-object questions (e.g., hung4zai2 sek3 bin1go3? [Bear kiss who?]) reflects the same subject, verb, object order typically used for declarative sentences, and a movement account provides no basis for expecting special difficulties with such questions. As in English, however, Cantonese who-object questions occur less frequently than do who-subject questions. A comparison of preschoolers with SLI, typically developing same-age peers, and younger, typically developing peers revealed that the children with SLI were less accurate in using who-object questions than either of the other participant groups yet showed no differences from these groups in the use of who-subject questions (e.g., bin1go3 sek3 zyu1zyu1? [Who kiss Piglet?]). The implications of these findings for current accounts of SLI are discussed, and the idea that input frequency and animacy may play a larger role than is often assumed is suggested.

Analysis of Variance↗

PubMed2002

The interaction of ambient frequency and feature complexity in the diphthong errors of children with phonological disorders.

This study examined the interaction of ambient frequency and feature complexity in the diphthong errors produced by Cantonese-speaking children with phonological disorders. A total of 611 diphthongs produced by 13 Cantonese-speaking children with speech disorders were subjected to perceptual analysis. The percentage accuracy of production and error patterns was examined. Perceptual analysis showed that /(see text)i/ and /ui/ were most frequently in error, whereas /ei/, /ou/, and /(see text)u/ were least frequently in error. Diphthong errors (usually diphthong reduction) arise as a function of both ambient frequency and feature complexity. The combination of ambient frequency and feature complexity yields a complexity metric reflecting accuracy of production. Treatment guidelines include consideration of three basic factors: ambient frequency, feature complexity, and error patterns.

Child↗

PubMed2002

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.

Child↗

PubMed2002

Feature development in Cantonese.

The phonetic inventories of 122 typically developing Cantonese-speaking children, aged from 0;10 to 4;7, were examined in terms of feature distinctions. The applicability of Dinnsen. Chin, Elbert and Powell's implicational feature hierarchy to these data was investigated. Results show that modifications to the hierarchy are necessary for the Cantonese phonetic system. A revised hierarchy for Cantonese is proposed. Differences between this proposal and the original work are discussed. The implicational nature of the proposed hierarchy was also tested on longitudinal data from ten children (aged from 0;10 to 3;5 at the beginning of the study) over a 1 year period. The proposed hierarchy successfully predicted the route of sound change of these inventories. Implications for further research on feature development are discussed.

Child Language↗

PubMedDate not supplied

Levels of complexity in phonological disorders: evidence from Cantonese.

Longitudinal data from ten phonologically disordered Cantonese-speaking boys were analysed for distinctive features (manner and place). The children labelled 95 pictures, attempting each initial Cantonese segment at least five times. The applicability of Dinnsen et al.'s implicational hierarchy to this data was examined. Categorization of each child's system according to an implicational hierarchy was successful for nine of the ten children when phonetic inventories were considered. In addition, a phonemic inventory based on Dinnsen et al.'s phonetic inventory captured the system of phonological contrasts used by eight of the ten children. The patterns of the children who did not match the hierarchy were considered deviant rather than delayed. The ability of the hierarchy to predict the route of development in this group of children was also examined. The hierarchies (both phonetic and phonemic) successfully predicted the route of change in these cases. Implications for the use of an implicational hierarchy in phonological assessment and treatment are discussed. Further research on feature-based phonological development, in both typically-developing and disordered phonological systems is required.

Articulation Disorders↗