Chapter 6 reports on an ERP experiment with a picture–sentence matching task, in which a picture was presented before the corresponding sentence. The target sentences used in this experiment were the same as those used in the experiment reported in Chapter 5, i.e., transitive sentences with thematically reversible agents and patients, arranged into four word orders: VOS, VSO, SVO, and OVS. The results of this experiment also demonstrated that SVO elicited a P600 compared to VOS, and that VSO elicited a similar posterior positivity, relative to VOS. The results of the two ERP experiments combined clearly indicate that VOS is the syntactically simplest and easiest-to-process word order of the grammatically possible ones in Kaqchikel, which is in line with our previous findings, described in Chapters 3 and 4. In short, Chapters 3 to 6 present data showing that a VOS preference was observed in Kaqchikel sentence comprehension, which provides empirical support for the IGV.

Chapter 5 investigates the time course of the processing of Kaqchikel sentences with alternative word orders. A sentence–picture matching task was employed in an experiment measuring event-related potentials (ERPs). In this experiment, a Kaqchikel sentence was presented aurally through a headset; afterwards, a picture was presented in the center of a screen, either matching the event described by the preceding sentence or not. Upon seeing the picture, the participants were asked to judge whether the picture was congruent with the sentence. The target sentences used in this experiment were all transitive, with thematically reversible agents and patients, arranged into four word orders: VOS, VSO, SVO, and OVS. A late positive ERP component called P600 was used to examine processing loads, as P600 has been found to be elicited by sentences with a filler-gap dependency, reflecting an increased syntactic processing cost. The results of the two experiments demonstrated that SVO elicited a greater positivity (P600) than VOS, and that VSO elicited a similar posterior positivity, relative to VOS. This range of properties follows naturally from the combination of the IGV and the syntactic structures of Kaqchikel transitive sentences given in Chapter 2.