Neural basis of syntactic processing of simple sentences in Japanese.

This study used event-related functional magnetic resonance imaging to investigate the neural basis underlying the sequential involvement of syntactic processing in the course of sentence comprehension. In experiments, a noun, case particle, and verb were presented one by one, constituting simple sentences in Japanese. Participants judged whether the sentence was syntactically correct (syntactic judgment) or whether the particle and verb had the same vowel (phonological judgment). During particle presentation, greater activation in the left inferior frontal gyrus was observed during syntactic judgment than during phonological judgment. Presentation of verbs subsequently activated the left dorsal prefrontal cortex and medial superior frontal areas in the same comparison. Our findings indicate that these regions are sequentially recruited in the syntactic processing of simple sentences in Japanese.