Parafoveal N400 effect during sentence reading.

Research has suggested that during reading, parafoveal information pertaining to the next word in a line might be, at least partially, processed. We used event-related brain potentials (ERPs) to examine this issue. Volunteers read sentences presented word-by-word at fixation with each word flanked bilaterally on its right by the next word in the sentence and on its left by the preceding word. Infrequently, the right flanker was replaced by a word that was semantically incongruous with the ongoing sentence context. N400 amplitudes to the critical triads were smaller when the right flanker was contextually congruent than incongruent, indicating that parafoveal information was extracted and quickly and incrementally integrated within the evolving sentence representation.