Effects of Syntactic Distance and Word Order on Language Processing: An Investigation Based on a Psycholinguistic Treebank of English.

We conducted a broad-coverage investigation of the effects of syntactic distance and word order on language processing against a dependency-annotated reading time corpus of English. A combined method of quantitative syntax and psycholinguistic analyses was adopted to yield converging evidence. It was found that (i) head-initial structures allow greater structural complexity, i.e., larger head-dependent distance, than head-final structures in both language comprehension and production; (ii) within the capacity limit of working memory, syntactic distance is a positive predictor of reading time for a word with a preceding head, whereas a negative predictor of reading time for a word with a following head; and (iii) at the sentence level, syntactic distance is a significant predictor of sentence reading time. These results suggest that (i) different word orders may enjoy different processing mechanisms in terms of cognitive difficulty and processes, which can be explained by an incremental language parser; and (ii) in addition to distance, word order should also be considered as a factor affecting language processing, which is an important extension to distance-based language processing models. Taken as a whole, our study paves the way for corpus-based integration of quantitative linguistic and psycholinguistic methods into understanding language processing and its underlying cognitive mechanisms.