Semantic integration processes at different levels of syntactic hierarchy during sentence comprehension: an ERP study.

An event-related potential (ERP) study was conducted to investigate the temporal neural dynamics of semantic integration processes at different levels of syntactic hierarchy during Chinese sentence reading. In a hierarchical structure, subject noun+verb+numeral+classifier+object noun, the object noun is constrained by selectional restrictions of the classifier at the lower-level and of the verb at the higher-level and the classifier is also constrained by the verb at the higher-level. Semantic congruencies between verb, classifier, and noun were manipulated, resulting in five types of sentences: correct sentences, sentences with the single classifier-noun mismatch, sentences with the single verb-noun mismatch, sentences with the double-mismatch in classifier-noun and verb-noun, and sentences with the triple-mismatch in classifier-noun, verb-noun and verb-classifier. Compared with correct sentences, all four types of mismatches elicited N400 effects on the noun, with the effect in the double-mismatch equal to the effect in the single classifier-noun mismatch but larger than the effect in the single verb-noun mismatch. In addition, the single verb-noun mismatch and the double-mismatch elicited a left-posterior positivity effect and an anterior negativity effect in the 550-800 ms time window on the noun, with the effects larger in the double-mismatch than in the single-mismatch. The classifier-noun mismatch also elicited the late anterior negativity effect on the noun. Although the triple-mismatch did not induce a significant late positivity effect on the noun, it did on the classifier. The pattern of the N400 effects suggests that semantic processes at different levels of syntactic hierarchy interact in integrating the incoming word into the prior sentence context with neither process overriding the other. The late-posterior positivity effect may reflect the coordination of various semantic integration processes across hierarchical levels during sentence comprehension.