Approaching normal reading: SOA, frequency, and predictability effects on event-related potentials

To avoid overlapping components elicited by consecutive words, event-related potentials (ERPs) during reading are usually recorded while sentences are presented word-by-word with unnaturally long stimulus onset asynchronies (SOAs). Because artificial presentation rates make data difficult to compare with normal reading, we examined the influence of SOA on ERPs using standard (700 ms) and quasi-normal (280 ms) intervals between sequentially displayed words of 144 sentences. In addition, frequency as bottom-up and predictability as top-down variables were experimentally manipulated on target words. Apart from influences of frequency and predictability on the time-course of word recognition, we expected SOA to affect early and late ERP components. Furthermore, relations to fixation durations from an independent eye-movement study utilizing the same stimulus material were explored.