Early lexical influences on sublexical processing in speech perception: Evidence from electrophysiology

Contextual information influences how we perceive speech, but it remains unclear at which level of processing contextual information merges with acoustic information. Theories differ on whether early, sublexical speech processing levels are strictly feed-forward or are influenced by semantic and lexical context. Studies using behavioral responses have shown contextual factors influence sublexical judgments but are unable to pinpoint whether context biases responses by modulating sublexical processing or later response selection stages. In the current study, we investigate the time-course of context effects by simultaneously recording electroencephalography as an online measure of sublexical speech processing while subjects engage in a lexically biasing phoneme categorization task. We find that lexical context modulates the amplitude of the N100, an ERP component linked with sublexical processes in speech perception. These results support interactive accounts of speech perception over accounts in which early speech perception processes are only driven by bottom up information.