Listener characteristics modulate the semantic processing of native vs. foreign-accented speech

Foreign accents have been shown to have considerable impact on how language is processed [1]. However, the impact of a foreign accent on semantic processing is not well understood. Conflicting results have been reported by previous event-related potential (ERP) studies investigating the impact of foreign-accentedness on the N400 effect elicited by semantic violations. Furthermore, these studies have only examined a subset of the four characteristics of the N400 (i.e. onset latency, latency, amplitude, and scalp distribution), and have been conducted in linguistic environments where foreign-accented speech is relatively uncommon. The current study therefore compared the N400 effect elicited by semantic violations in native Australian English vs. Mandarin-accented English, in a context where foreign-accented speech is common. Factors which may be responsible for individual variability in N400 amplitude were also investigated. The results showed no differences between the N400s elicited by native and foreign-accented speech in any of the four aforementioned characteristics. However, the analysis of individual variability revealed an effect of familiarity with foreign-accented speech on the amplitude of N400 effects for semantic violations. An effect of working memory capacity on N400 amplitude was also found. These findings highlight the relevance of the ambient linguistic environment for studies of speech processing, and demonstrate the interacting influences of both speaker- and listener-related factors on semantic processing.