The Interaction of Morphosyntactic and Semantic Processing in Japanese Sentence Comprehension: Evidence from Event-Related Brain Potentials

The present study examined event-related brain potential (ERP) responses to apparent Case-assignment violations to explore how morphosyntactic and semantic processing interact with each other during Japanese sentence comprehension. Consistent with previous studies on Case-assignment violation, the present results found that a Case-assignment violation elicited a left anterior negativity (LAN), followed by a posterior P600 compared with its grammatical counterpart. Crucially, the LAN-P600 effects were also elicited by a morphosyntactically well-formed sentence with a thematic implausible argument that may potentially force the sentence processor to perceive an apparent Case-assignment violation. Provided that the LAN effects can be interpreted as a morphosyntactic violation effect, these findings suggest that the morphosyntactic and semantic processing streams operate at least partially in parallel during sentence comprehension and that they begin to interact with one another at approximately 400 ms (at the latest) after encountering a verb.*