Neural correlates of cross-alphabetic interference and integration in the biliterate brain

We investigated the neurophysiological mechanisms underlying bi-alphabetic reading using event-related potentials (ERPs). Brain activity was recorded using EEG in a group of Russian–English biliterates during a reading-aloud task with familiar and novel words. Capitalizing on a partial overlap between the Roman and Cyrillic alphabets, the stimuli were presented in L1 Cyrillic, L2 Roman, or in an ambiguous script, in a counterbalanced fashion. The results revealed functional dissociation between the stimuli in terms of processing their graphemic ambiguity. The interference caused by L1-L2 script inconsistencies in novel wordforms was detected at a late processing stage, reflected in N400 response enhancement for unfamiliar script-ambiguous items. Conversely, familiar ambiguous and L2 words showed no N400 increase but demonstrated an early enhancement of the P200 component in comparison to those presented in L1. These results indicate the use of a whole-word reading strategy for familiar words even in ambiguous script, likely triggered by an automatic activation of well-established lexico-semantic representations. The absence of similar top-down mechanisms for novel ambiguous-script words likely results in increased grapheme-to-phoneme decoding effort, with important implications for L2 reading and vocabulary acquisition.