Uncertainty in processing relative clauses across East Asian languages

The processing difficulty profile for relative clauses in Chinese, Japanese and Korean represents a challenge for theories of human parsing. We address this challenge using a grammar-based complexity metric, one that reflects a minimalist analysis of relative clauses for all three languages as well as structure-dependent corpus distributions. Together, these define a comprehender's degree of uncertainty at each point in a sentence. We use this idea to quantify the intuition that people do comprehension work as they incrementally resolve ambiguity, word by word. We find that downward changes to this quantitative measure of uncertainty derive observed processing contrasts between Subject- and Object-extracted relative clauses. This demonstrates that the complexity metric, in conjunction with a minimalist grammar and corpus-based weights, accounts for the widely-observed Subject Advantage.