Comprehension of double-center embedded relatives in Italian: a case for hierarchical intervention

Object relatives are more difficult to process than subject relatives. Several sentence processing models have been proposed to explain this difference. As double-center embedding relatives contain several long-distance dependencies, they are an ideal configuration to compare sentence processing models. The main aim of the present study was to compare the predictions of the featural Relativized Minimality approach with the ones of other relevant sentence processing models. 57 Italian-speaking healthy adults answered comprehension questions concerning the first, second, or third verb to appear in both double-center embedding and control sentences. Results show that questions concerning the matrix verb of double-center embedding structures were significantly easier and were associated with faster response times than questions concerning the embedded verbs. Furthermore, in object double-center embedding relatives the questions concerning the verb of the most embedded clause were easier than the ones concerning the verb of the intermediate embedded clause. This pattern of results is consistent with featural Relativized Minimality but cannot be fully explained by other sentence processing models.