Dr. Kerry Proctor-Williams, Department of Communicative Disorders, receives NIH funding for an intervention study for children with language impairment.
Dr. Proctor-Williams, who received her Ph.D. from the University of Kansas in 2005, is extending her research on interventions to improve grammatical development in preschool-aged children with language impairments. This study will investigate the effects of a language intervention technique to facilitate grammatical development.
This technique, called recasting, is a procedure that corrects children's grammatical mistakes by restating their sentence using correct grammar. The study will examine the dosage of recasting necessary to effect changes in the children's grammar with 24 children with language impairments and 24 typically developing children. Dr. Proctor-Williams' research interests include children's early language development and disorders, treatment approaches for child language delay and disorders and service delivery models.
Children with specific language impairment (SLI) lag behind children with typical language development (TL) in their grammatical development, despite equivalent early exposures to a form of adult grammatical corrections in conversation, called recasts (Fey et al., 1999), and their demonstrated ability to learn from recasts in intervention as quickly as do children with TL (Nelson et al., 1996).
Recasts are immediate adult responses to child utterances that repeat some of the child's words and correct or otherwise modify the morphologic or syntactic form of the child's prior utterance, while maintaining the central meaning of the child's production. For example, if a child said "It falled down", an adult corrective recast would be "It fell down".
From one theoretical view, the basis of the grammatical problems of children with SLI involves limitations in working memory, and processing speed and capacity (Leonard et al., 2007). Leonard et al. suggest that intervention approaches that decrease processing demands and offer multiple repetitions of words and sentences have the potential to override processing limitations. The facilitative properties of recasts and the flexibility of their use in treatment give them the capability to fulfill these conditions.
The question remains, however, how can clinicians employ recasts in intervention most efficaciously? Warren et al. (2007) suggest that it is time for the field of child language to begin specifically investigating components of treatment intensiveness, such as dosage, and their impact on treatment efficacy.
Currently, such research is virtually nonexistent. The proposed study will begin to fill this gap through examination of two specific aspects of dosage; recast rate and recast distribution. The specific aim of this study is to determine how rate and distribution of recasts affects acquisition of irregular past tense of novel verbs, by 24 children with SLI (4 and 5 year olds) and 24 younger, language equivalent, children with TL (3 year olds).
This study, which utilizes a multi factor between groups design, includes two independent experimental tasks. Experiment 1 examines the children's learning of two irregular past tense novel verbs (dake-doke and kig-kug) in response to one of three rates of recasts, 0.5/min, 1.0/min or 1.5/min, over five sessions. Experiment 2 examines the children's acquisition of two different irregular past tense novel verbs (jare-jore and twink-twank) when given 20 verb exposures each in 1,2 or 5 sessions. Outcome variables include percent of accurate production in obligatory contexts of the target verbs during the sessions and on post-test probes.
This research proposal represents the fourth study in a path of research that has three long-term goals: (1) establishment of efficacious early intervention techniques that will contribute to the amelioration of the long-term interpersonal and academic consequences of SLI; (2) a detailed understanding of language processing limitations that affect morphosyntactic acquisition of children with SLI; and (3) development of a dynamic assessment protocol that distinguishes late-talking toddlers with SLI from those with TL. The methodology and results of the proposed study will contribute significantly to future randomized clinical trials.
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Promoting Speech and Vocabulary Development through Specialized Storybooks in Children with and without Cleft Palate
Smith, J. M.S. - Scherer, N.J., Ph.D. - Kaiser, A. Ph.D.
East Tennessee State University
This study investigated changes in vocabulary and speech sound production in response to storybooks embedded with Enhanced Milieu Teaching language prompts and speech recasts. Six children received the intervention, three with cleft lip and palate (CL/P), displaying speech and language delays, and three language-matched children with non-clefts, each 12-24 months of age. A multiple baseline design across behaviors was implemented by a trained graduate clinician.
Results indicated that all children increased their use of the target vocabulary and speech sound production of stop consonants, while reducing compensatory articulation errors. Generalization of the targets to a novel picture-naming task was also observed, as was generalization to a free play task, and to the home as reported by the parents. Effect sizes were moderate to high for all children. The children with CL/P required more treatment sessions to achieve criterion than the non-cleft children. Analysis of 20-minute language samples, given pre- and post-intervention for each participant, showed that both groups of participants increased their expressive vocabulary and speech production measures post intervention.
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