Effects of animacy and noun-phrase relatedness on the processing of complex sentences.

Previous work has suggested that syntactically complex object-extracted relative clauses are easier to process when the head noun phrase (NP1) is inanimate and the embedded noun phrase (NP2) is animate, as compared with the reverse animacy configuration, with differences in processing difficulty beginning as early as NP2 (e.g., The article that the senator . . . vs. The senator that the article . . .). Two eye-tracking-while-reading experiments were conducted to better understand the source of this effect. Experiment 1 showed that having an inanimate NP1 facilitated processing even when NP2 was held constant. Experiment 2 manipulated both animacy of NP1 and the degree of semantic relatedness between the critical NPs. When NP1 and NP2 were paired arbitrarily, the early animacy effect emerged at NP2. When NP1 and NP2 were semantically related, this effect disappeared, with effects of NP1 animacy emerging in later processing stages for both the related and arbitrary conditions. The results indicate that differences in the animacy of NP1 influence early processing of complex sentences only when the critical NPs share no meaningful relationship.