Processing Italian relative clauses: Working memory span and word order effects on RTs

In this study, the authors aim to clarify whether the subject–object asymmetry in relative clause comprehension is due to the use of parsing strategies (Active Filler Theory) or to a greater memory load generated by object sentences. Two experiments investigate how individual differences in working memory span may influence the reading times of relative sentences in Italian, a language characterized by a flexible structure. The results of Experiment 1 indicate that object extraction is more complex than subject extraction when sentences have a canonical structure. Furthermore, low-span participants have particular difficulties with object relative sentence comprehension. The results of Experiment 2 show that subject-relative clauses with uncanonical structures are more complex to understand than object-relative clauses, and low-span participants have more difficulties than high-span participants in elaborating both subject and object relative clauses. These data seem to be coherent with the Active Filler Theory.