Second language learners’ processing of inflected words: Behavioral and ERP evidence for storage and decomposition

This study reports the results of two behavioral and two event-related brain potential (ERP) experiments examining the processing of inflected words in advanced second language (L2) learners with Russian as their native language (L1) who learnt German as an L2 after childhood. Two different subsystems of German inflection were studied, participial inflection and noun plurals. For participial forms, L2 learners were found to widely generalize the -t suffixation rule in a nonce-word elicitation task, and in the ERP experiment they showed an anterior negativity followed by a P600 – both results resembling previous findings from native speakers of German on the same materials. For plural formation, the L2 learners displayed different preference patterns for regular and irregular forms in an off-line plural judgment task. Regular and irregular plural forms also differed clearly with regard to their brain responses. Whereas -s plural regularizations produced a P600 component, irregularizations elicited an N400. In contrast to native speakers of German, however, the L2 learners did not show an anterior negativity for -s plural regularizations. Taken together, the results show clear dissociations between regular and irregular inflection for both morphological subsystems. We argue that the two processing routes posited by dual-mechanism models of inflection (lexical storage and morphological decomposition) are also employed by L2 learners, even though the decomposition route appears to be more limited in the L2 learners than in the native controls.