Grant: Discovery Grants Program - Individual

Individual variability in language abilities is often discarded from scientific investigation. A comprehensive account of language processing, however, requires consideration of commonalities as well as individual differences. The long-term goal of my research is to provide a detailed account of the neurocognitive mechanisms underlying individual differences in language processing. This account will explain how language-specific (e.g., lexical knowledge) and domain-general (e.g., working memory) mechanisms contribute to individual differences in language processing. It will establish a link between linguistic behaviour and brain responses. Finally, it will apply to populations with different linguistic profiles. Using a number of innovative methodological approaches and adhering to the current standards of reproducible and transparent science, I will pursue the following short-term aims. Aim 1 is to assess reliability and stability of several behavioural and electrophysiological measures of language processing. Measures found to be stable within individuals will be used as indicators of individual performance in further studies. Aim 2 is to advance a technique of functional localization of regions of interest to the field of electrophysiology. This innovative methodological approach will allow me to account for variability in locations of functional areas dedicated to language in the individual brains. In Aim 3, I will explore inter-individual variations in behavioural and neural responses during language processing across 3 populations with distinct linguistic profiles: (i) monolinguals, (ii) bilinguals, and (iii) individuals with autism spectrum disorders (ASD), a group characterized by impaired processing of language. The proposed research will provide an in-depth evaluation of associations between behavioural and neural responses evoked during language processing and will advance our understanding of effects that language-specific and domain-general cognitive mechanisms have on individual differences in linguistic abilities. The obtained knowledge about factors contributing to variability in linguistic skills will inform educators, who will use this information to create programs tailored to the cognitive strengths of an individual. Finally, this research will make a number of methodological contributions, including (i) a comprehensive assessment of stability of several language comprehension measures, (ii) an introduction of the method of functional localization of EEG channels/regions of interest, and (iii) a validation of several analysis techniques applied to EEG/ERP data (i.e., latent difference score modeling (LDS) and representational similarity analysis (RSA)). To conclude, the proposed research will allow me to make significant advances in understanding mechanisms of linguistic diversity.