The neural bases of argument structure processing revealed by primed lexical decision.

Previous studies have reported anticipatory effects during sentence processing. However, the source of these effects has not been clearly characterized. This study investigated the hypothesis that one source of anticipatory effects, particularly during verb processing, is the automatic triggering of argument structure processes. If argument structure processes are automatically triggered it was hypothesized that the task need not require the initiation of the process, as such a primed lexical decision task was used that examined the neural priming of cross-grammatical class prime pairs (e.g., verb-noun priming). While previous studies, as does the current study, have revealed behavioral priming for cross-grammatical class and within-class (noun-noun and verb-verb) prime/target pairs, the current results revealed significant activation differences. Enhancement effects were observed for cross-grammatical class priming in the language network, particularly the inferior frontal gyrus (BA 47), and the posterior temporal cortex. Both regions have been linked to argument structure processing previously. Within-class priming resulted in neural suppression of the inferior temporal/occipital regions. Together, the data presented suggest the automatic triggering of argument structure representations and demonstrate that priming is a fruitful mechanism to explore aspects of sentence processing.