Verb argument structure complexity is manifested in four aspects: the number of arguments, the selection mode of arguments subcategorization, the assignment mode of θ-roles and the mapping of argument structure. Most empirical studies show that more arguments, alternating arguments subcategorization, alternating assignment of θ-roles and noncanonical mapping make the cognitive neural mechanisms of verb argument structure processing become more complicated. The main functional brain regions corresponding to processing of more arguments involve left inferior frontal gyrus and posterior perisylvian regions, the main functional brain regions corresponding to processing of alternating argument subcategorizations involve left inferior frontal gyrus, middle-posterior frontal lobesuperior temporal gyrus and middle-posterior temporal lobe, the main functional brain regions corresponding to processing of alternating assignment mode of θ-roles involve posterior perisylvian regions, left middle-posterior frontal lobe and inferior frontal gyrus, the main functional brain regions corresponding to processing of noncanonical mapping involve left inferior frontal gyrus, superior temporal gyrus, middle temporal gyrus and posterior temporal lobe. Perhaps, left inferior frontal gyrus involves initial syntactic processing, the determination of the subcategory of verbs, syntactic movement processing and semantic processing of unaccusative verbs, left middle-posterior frontal lobe involves initial syntactic processing and the determination of the subcategory of verbs, left superior temporal gyrus and middle-posterior temporal lobe involve surface syntactic structure processing and argument syntax-semantic integration, posterior perisylvian regions involve argument semantic reprensatation. The process of verb argument structure processing and lexical properties of verbs indicate that there are interaction effects between or among some complexities. Some other issues need further exploration, including the corresponding relationship between the complexity of the verb argument structure and the difficulty of its processing, the difficulty hierarchy of verb argument structure complexities processing and the cognitive neural mechanisms of interaction effects of them, as well as the cognitive neural mechanisms of Chinese verb argument structure complexity processing.
