Bilinguals reading in their second language do not predict upcoming words as native readers do

During reading, monolingual readers actively predict upcoming words from sentence context. Here we investigated whether bilingual readers predict sentence final words when they read in their second language. We recorded event-related potentials while English monolinguals (L1 comprehenders) and late Spanish-English bilinguals (L2 comprehenders) read sentences ending in an expected or unexpected noun. Lexical prediction was indexed by the amplitude of the N400 effect elicited by the article preceding the final noun, such that the more negative the N400, the less prediction as regards the final word. Contrary to L1 comprehenders, L2 comprehenders failed to show an N400 amplitude increase for unexpected articles. We interpret these results as evidence that L2 comprehenders do not actively predict upcoming words during sentence comprehension to the same extent as L1 comprehenders. This weaker capacity of lexical prediction in L2 might be one of the consequences of overall slower and less accurate linguistic processing stages in L2 relative to L1.