Event-related potentials elicited during parsing of ambiguous relative clauses in Spanish.

Previous behavioural studies in Spanish have found a significant preference for attaching relative clauses preceded by a complex NP (N1 of N2 RC) to the first noun phrase. In the present study, we used event-related potentials (ERPs) to help identify the nature of these processes by directly comparing ERPs to temporary ambiguous sentences containing relative clauses that were finally consistent with either high or low attachment resolution. The larger amplitude of the P600 effect for the low attachment condition suggests that high attachment was the preferred strategy. The P600 effect was widely distributed in the 500-700 ms window, including frontal areas, while the distribution was mainly posterior in the 700-1000 ms window. The results indicate that high attachment is the parsing strategy Spanish readers use for this type of ambiguity and suggest that the P600 may not be a monolithic effect.