When embeddedness matters: Electrophysiological evidence for the role of head noun position in Chinese relative clause processing

This ERP study of Chinese subject- and object-modifying relative clauses (RCs) aimed at investigating how sentence context (embeddedness) temporally interacted with relativization in terms of processing load. In stead of adotping a static view of processing costs of RCs, we focused on the dynamic modulation of processing load by sentence context at two critical words-the relative marker de and head noun. Using cluster-based permutation analyses of ERPs, our study found an early relativization effect (110-220 ms) followed by an embeddedness effect (411-441 ms) and a late interaction effect (540-620 ms) at the relative marker de. The main effect of relativization as an early left anterior negativity suggests a transitory processing advantage of subject-relativization independent of sentence context. The sentence context was processed just 410 ms after word onset as a late left-lateralized anterior negativity for the center-embedded RCs, indicating increased working memory load introduced by sentence context constraints. A late centro-posterior positivity registered for object-relativization RCs with preceding sentence context due to structural reanalysis. An early anterior negativity (73-123 ms) reflecting the embeddedness effect at the head noun suggests the complexity of information encoded in phrase markers when semantic contents of verb arguments are instantiated. Our results indicate that it is necessary to adjust the account of RC processing beyond a universal processing advantage for subject-relativization to integrate the effects of sentence context cross-linguistically.