An investigation of nominal copular sentences in three reading paradigms: Acceptability judgments, self-paced reading, and eye-tracking

This work aims to investigate the elaboration of (nominal) copular sentences in three different experimental paradigms involving a reading task: an acceptability judgment, a self-paced reading and an eye-tracking experiment. Nominal copular sentences (NCs), such as [DP1 The picture of the wall] is [DP2 the cause of the riot], represent a challenging phenomenon for, at least, two reasons: (i) they can be distinguished in two subtypes, namely canonical and inverse NCs, related to the different order of the DPs (respectively, [DPsubject is DPpredicate] in canonical form vs. [DPpredicate is DPsubject] in inverse form); (ii) these two subtypes are associated with one and the same type of string [DP is DP], although their underlying structure is completely different. Our results show that no differences emerge in the off-line paradigm, i.e. in the acceptability judgments. On the other hand, the self paced-reading task and the eye-tracking experiments show an asymmetry between these two types of NCs, with higher processing costs for inverse NCs. More specifically, the DPsubject is looked at more often and for longer times in inverse NCs. Moreover, when comparing the DPsubject to the DPpredicate in postverbal position in the eye-tracking experiment, sentence structure resulted as a good predictor for total reading time and regression path duration, even after taking into account the length and frequency of the words used. These results strongly support the hypothesis that syntactic structure is a primary factor in generating a different reading pattern between the same string of lexical types of items.