whether the stimulus presented is a word or a non-word. Within this framework, the semantic priming task has been one of the most extensively used paradigms to observe the effect of priming on N4 (Bentin, 1989; Ganis et al., 1996). Classically, with respect to behavioral studies, semantic priming effect refers to the faster reaction time to the related targets than to the unrelated targets in a lexical decision task (Meyer and Schvaneveldt, 1971). Similarly, with regard to ERP tasks, semantic priming is observed in reduced N4 amplitude to the primed stimuli. A body of early work shows that, N4 amplitude is inversely related to the word’s ‘cloze probability’ (Kutas and Hillyard, 1984), i.e., the degree to which a particular word is the most likely completion for a sentence fragment (Taylor, 1953). For example, in the sentence, ‘I had coffee and omelet for breakfast’, the last word ‘breakfast’ has a greater degree of probability and/or association to complete the sentence, than the word ‘office’. Recently it has been shown that the N4 amplitude reduction observed to a primed stimulus, such as in antonym-pairs, is similar to the N4 amplitude reduction observed to congruent last words in sentences (Kutas and Federmeier, 2000).
