Wednesday, May 18, 2011

A Clinical Rationale for Assessing Rapid Automatized Naming in Children with Language Disorders

Wiig, E.H., Zureich, P., & Chan, H-N.H. (2000). A clinical rationale for assessing rapid automatized naming children with language disorders.

Word finding difficulties characterize many children with language difficulties. One challenge in assessing these difficulties is determining whether the difficulty is related to poor word knowledge or difficulty retrieving known word knowledge. This study examines the utility of rapid automatized naming (RAN) to distinguish these difficulties.

RAN tasks involve the rapid retrieval of known words. The items to be named are typically familiar words so the focus of the task is on retrieval. A task may involve the naming of items from a single domain (e.g., letters, colours), or more than one domain (e.g., alternating letters and numbers; naming colour and shape). The integration of more than one feature requires accessing and inhibiting responses, and reflects interference effects. Greater interference effects may indicate greater difficulty in successfully retrieving words.

RAN difficulties for letters, numbers, and alternating letters and numbers have been demonstrated for children with dyslexia (e.g., Wolf, 1991, Reading Research Quarterly, 26, 123-141). Wolf has proposed a double deficit hypothesis (see our blogpost for October 31, 2010) suggesting that phonological processing and naming speed deficits constitute two core and separable deficits in dyslexia.

The present study employed the RAN tasks of the Clinical Evaluation of Language Fundamentals-3 (Semel et al., 1995) involving rapid naming of (1) colours, (2) shapes, and (3) colours and shapes to compare groups of children with language impairment and typical development. The groups were reliably distinguished on the 3rd task requiring the rapid naming of both shape and colour only.

The authors suggest that the RAN tasks may identify whether a naming-speed deficit and interference with fluency in language production is problematic. Slower naming on all 3 tasks may suggest pervasive slowing in language production while slower naming on the 3rd task only may reflect slower naming speed and interference impairments that effect fluency in language production. Normative data for the RAN tasks are provided in the paper.

Blogger: Lisa Archibald

Monday, May 16, 2011

The Relation Between Teacher Input and Lexical Growth of Preschoolers

Bowers, E.P., & Vasilyeva, M. (2011). The relation between teacher input and lexical growth of preschoolers. Applied Psycholinguistics, 32, 221-241.

This study examined the relationship between teacher speech and vocabulary (lexical) growth in 29 English language learners (ELL) of varying native languages, and 75 monolingual English preschoolers over the course of one academic year. Children’s lexical or word knowledge was assessed at the beginning and end of the same academic year using a well-accepted standardized vocabulary test, the Peabody Picture Vocabulary Test – Third Edition (PPVT-IIIB). In the middle of the school year, samples of teacher input were recorded from 10 classrooms over a 1.5 hour period that included circle time (group instruction), and snack time. Teacher speech was measured by input quantity (total number of words), lexical diversity (number of different words), and structural complexity (average number of words per utterance).

Results indicated that while the lexical growth of monolingual English speakers was significantly and positively related to the lexical diversity of teacher input with a relatively small effect size. In contrast, the lexical growth of ELLs was significantly and positively related to the quantity of teacher input but significantly and negatively related to the complexity of teacher input.

A possible explanation for this finding is that monolingual English preschoolers have already mastered the basics of English, and are therefore not thrown off by the lexical diversity. Instead, these children’s lexical growth is dependent on exposure to new words. In comparison, the ELL children have not yet mastered the basics of English and can be thrown off by the cognitive demand of complex utterances. These children benefit more from repetition of English words in simple sentences.

The main limitations of this study are the small sample size, particularly with respect to the ELL group, the single sample of teacher speech, and the lack of information provided about the teaching context (experience, class size, etc.). The strengths of this study include the novelty of comparing teacher speech to lexical growth of preschoolers (as it is typically parental speech that has been studied), and the promising suggestive results and effect size despite the small sample size.

Although the data is suggestive, it offers a promising path for future research in the area of language development and teacher input particularly highlighting the need to repetition in simple sentences to promote growth of word knowledge in children learning English whose first language is not English.

Blogger: Laura Vanderlaan