Specific language impairment (SLI) affects over 7% of US children and is associated with increased risk of academic and work-related problems. A key feature of SLI is difficulty learning new words;yet the nature of this difficulty is poorly understood. Both phonological memory and semantic processing deficits have been proposed to account for word learning problems in SLI. While there is some evidence for each proposal, previous studies have yielded mixed results. Given that the two proposals may suggest different approaches to assessment and intervention, there is a critical need to understand the relative contributions of phonological and semantic deficits to word learning in SLI. Thus, an overarching aim of our research program is to clarify word learning profiles in SLI, and to relate these profiles to other language and cognitive profiles, including phonological memory and semantic processing skills and deficits. One reason for variability in past findings may be the use of heterogeneous samples. Many - but not all - children with SLI also have dyslexia (SLI-DYS). These children have deficits in phonological memory, as measured by nonword repetition tasks, as well as semantic deficits. However, there is also evidence that children with SLI in the absence of dyslexia (SLI-only) have intact nonword repetition. Past studies have tended to conflate the two samples. To address this issue, we will study phonological and semantic contributions to word learning in four subgroups: SLI-only, DYS-only, SLI-DYS, and typically developing (TD) children (Specific Aim 1). We hypothesize the word-learning difficulties in SLI and dyslexia have different underlying causes. We will test this hypothesis through careful examination of word learning processes in the four groups using standardized assessment, cognitive-behavioral tasks, and event-related potentials (ERP). In addition, we will determine how well word learning performance in grade 2 predicts growth in vocabulary knowledge and comprehension skills one year later (Specific Aim 2). The transition from grades 2 to 3 marks an important turning point in vocabulary and comprehension development. We predict that word learning performance in grade 2 will account for unique variance in vocabulary growth and comprehension in grade 3. We further predict that semantic skills, in particular, will help predict outcomes among SLI-only children. This project is innovative three ways: 1) in the separation of phonological and semantic aspects of word learning in SLI;2) in the separation of SLI-only and SLI-DYS samples;and (3) in the use of real-time ERP measures, which complement offline tasks. The long-term goal is to develop more effective assessments and better-targeted interventions for SLI, which would have a strong positive impact on public health outcomes.

Public Health Relevance

This project aims to contribute to a better understanding of the underlying deficits causing word-learning difficulties in children with specific language impairment (SLI) and/ or dyslexia. This project is relevant to NIDCD's mission to improve the lives of individuals with communication disorders because findings from the proposed studies are expected to be informative for developing better assessment and treatment methods for these disorders. The project is also relevant to the broader field of public health because of the importance of vocabulary knowledge, language, and literacy skills to quality of life outcomes.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
1R03DC013399-01
Application #
8576154
Study Section
Communication Disorders Review Committee (CDRC)
Program Officer
Cooper, Judith
Project Start
2013-07-01
Project End
2016-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
1
Fiscal Year
2013
Total Cost
$148,201
Indirect Cost
$43,370
Name
University of South Carolina at Columbia
Department
Other Health Professions
Type
Schools of Public Health
DUNS #
041387846
City
Columbia
State
SC
Country
United States
Zip Code
29208
Adlof, Suzanne M; Scoggins, Joanna; Brazendale, Allison et al. (2017) Identifying Children at Risk for Language Impairment or Dyslexia With Group-Administered Measures. J Speech Lang Hear Res 60:3507-3522
Adlof, Suzanne M; Patten, Hannah (2017) Nonword Repetition and Vocabulary Knowledge as Predictors of Children's Phonological and Semantic Word Learning. J Speech Lang Hear Res 60:682-693
Hendricks, Alison Eisel; Adlof, Suzanne M (2017) Language Assessment With Children Who Speak Nonmainstream Dialects: Examining the Effects of Scoring Modifications in Norm-Referenced Assessment. Lang Speech Hear Serv Sch 48:168-182
Adlof, Suzanne M (2017) Understanding Word Reading Difficulties in Children With SLI. Perspect ASHA Spec Interest Groups 2:71-77
Adlof, Suzanne; Frishkoff, Gwen; Dandy, Jennifer et al. (2016) Effects of induced orthographic and semantic knowledge on subsequent learning: A test of the partial knowledge hypothesis. Read Writ 29:475-500
Adlof, Suzanne M; Klusek, Jessica; Shinkareva, Svetlana V et al. (2015) Phonological awareness and reading in boys with fragile X syndrome. J Child Psychol Psychiatry 56:30-9