SELECTIVE ATTENTION AND N400 ATTENUATION WITH SPOKEN WORD REPETITION

In two experiments, event-related brain potentials were recorded to wo rd pairs simultaneously presented to both ears, with instructions to a ttend to one ear and detect occasional nonwords In that ear. This atte ntional manipulation yielded four patterns of word repetition on succe ssive trials: first and second presentations attended (AA), both unatt ended (UU), and across ears (AU and UA). A prominent attenuation of N4 00 due to immediate repetition of words was observed on AA trials. How ever, when first presentations were ignored an UU and UA trials, no re petition effect was obtained. These findings indicate that the repetit ion effect on N400 depends on attentional processing of first presenta tions.