Semantic knowledge, or knowledge of a word?s meaning, has strong ties to reading comprehension and long- term academic outcomes, particularly in the school years. Children with developmental language disorder (DLD), language impairment in the absence of any causal factors, often show deficits in semantic knowledge and acquisition. It is generally accepted that these deficits are driven by difficulty with the process of adding meaning to a new word with repeated exposures to the word, or configuration. What is unknown is what underlies deficits in configuration and whether these deficits vary across the DLD profile. The goal of this project is to elucidate the semantic learning deficits in DLD. Toward this goal, this project uses a combined electroencephalogram (EEG) - behavioral methods approach to examine the cognitive and linguistic processes engaged during semantic learning in school-age children with and without DLD. The inclusion of EEG will allow for a real-time examination of semantic learning and associated cognitive and linguistic processes. 10-12 year old children with and without DLD will complete a behavioral assessment battery and semantic learning task while their EEG is collected. Behavioral data will be analyzed for semantic learning group differences (Aim 1) and the types of errors that children make when they are unable to retrieve a correct meaning (Aim 2). EEG data will be analyzed in two ways. The event-related potential (ERP) analysis will examine changes in semantic processing, indexed by the N400, during learning (Aim 1). Time frequency analysis of the EEG will examine the engagement of neural processes associated with lexical retrieval (theta) and attention/inhibition (alpha) during learning (Aim 1). Behavioral and EEG methods will be combined to examine individual differences related to semantic learning outcomes and fine-grained differences in N400 learning effects across groups (Aim 2). Taken together, findings will inform our understanding of the nature of the semantic learning deficits in school-aged children with DLD. This understanding is prerequisite for targeted intervention that would help these children learn how to learn.
School age children with developmental language disorder (DLD) have known semantic learning deficits but what is less well understood is why semantic learning is difficult for these children. This project will combine behavioral and brain methods to investigate the cognitive and linguistic processes underlying semantic learning in children with DLD compared to typically developing peers. The outcomes will have implications for semantic learning intervention approaches in DLD.
