Neural Processes Associated with Vocabulary and Vowel-Length Differences in a Dialect: An ERP Study in Pre-literate Children

Abstract

Although familiarity with a language impacts how phonology and semantics are processed at the neural level, little is known how these processes are affected by familiarity with a dialect. By measuring event-related potentials (ERPs) in kindergarten children we investigated neural processing related to familiarity with dialect-specific pronunciation and lexicality of spoken words before literacy acquisition in school. Children speaking one of two German dialects were presented with spoken word-picture pairings, in which congruity (or the lack thereof) was defined by dialect familiarity with pronunciation or vocabulary. In a dialect-independent control contrast, congruity was defined by audio–visual semantic (mis)match. Congruity effects and congruity-by-dialect group interactions in the ERPs were tested by data-driven topographic analyses of variance (TANOVA) and theory-driven focal analyses. Converging results revealed similar congruity effects in the N400 and late-positive-complex (LPC) in the control contrast for both dialect groups. In the dialect-specific vocabulary contrast, topographies of the N400- and LPC-effects were reversed depending on familiarity with the presented dialect words. In the dialect-specific pronunciation contrast, again a topography reversal was found depending on dialect familiarity, however, only for the LPC. Our data suggest that neural processing of unfamiliar words, but not pronunciation variants, is characterized by semantic processing (increased N400-effect). However, both unfamiliar words and pronunciation variants seem to engage congruity judgment, as indicated by the LPC-effect. Thus, semantic processing of pronunciation in dialect words seems to be rather robust against slight alterations in pronunciation, like changes in vowel duration, while such alterations may still trigger subsequent control processes.