Poster C82, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Neuroimaging Evidence for Individual Differences in L1 Lexical Semantic Processing
Lisa Beck1, Lyam Bailey2, Morgan Johnson3, Ella C. Dubinsky4, Kaitlyn M. Tagarelli5, Timothy Bardouille6, Aaron J. Newman7; 1Dalhousie University
Previous models of native (L1) language processing have assumed that all L1 speakers show homogeneity in language proficiency and corresponding neural activity. However, there is a growing body of research suggesting that proficiency is not homogeneous within an L1 population, and that individual variability in this and in other cognitive factors may influence how and where in the brain language is processed. We investigated this relationship by using magnetoencephalography (MEG) to assess the time course, strength, and localization of neural activity associated with lexical semantic processing. This activity was elicited by the reading of either semantically congruent sentences (eg., Jenny lit the candles on the birthday cake), or anomalous counterparts containing a lexical semantic violation on the terminal word (eg.,*Jenny lit the candles on the birthday mine). Imaging data were analyzed in the 300-500 ms post-stimulus time window, with predictor variables including scores of language proficiency and other cognitive measures such working memory and executive functioning. Key findings include a positive correlation between the magnitude of the neural activity (the N400 effect) and grammar proficiency, as well as a right lateralization of this effect with increasing vocabulary proficiency. Our findings provide further evidence that there is individual variability in proficiency and other cognitive measures within a group of L1 speakers, and that these differences do modulate measurable characteristics of the neural activity associated with lexical semantic processing. Sensor- and source- level data will be used to demonstrate, both visually and quantitatively, the extent to which this modulation occurs.
Topic Area: LANGUAGE: Semantic