Аннотация:During a conversation, we are able to switch between different registers, which affects linguistic characteristics of the discourse. However, little is known about the influence of these changes on language processing. In the present study, we investigated the electrophysiological effect of register switching, reflected in vocabulary use (standard vs. non-standard vocabulary, e.g., slang). We analysed event-related potentials (ERPs) accompanying the processing of words that belong to a different register, relative to the sentence context (a slang word in a standard Russian sentence or a standard word in a slang sentence). As compared to the register congruent condition, these words elicited a prolonged N400, similarly to the semantically anomalous sentences. This indicates that integration of a word from incongruent vocabulary, during register switching, implicates additional lexical-semantic processing.