The role of discourse in long-distance dependency formation

Sentences with filler-gap dependency are more difficult to process than those without, as reflected by event-related brain potentials (ERPs) such as sustained left anterior negativity (SLAN). The cognitive processes underlying SLAN may support associating a filler with a temporally distant gap in syntactic representation. Alternatively, processing filler-gap dependencies in the absence of a supportive context involves additional discourse processing. The present study conducted an ERP experiment that manipulated syntactic complexity (subject–object–verb [SOV] and object–subject–verb [OSV]) and discourse (the supportive and non-supportive context) in Japanese. The result showed a SLAN in OSV relative to SOV in the non-supportive but not the supportive context, which suggests that the difficulty involved in processing OSV in Japanese is largely due to a pragmatic factor. The present study contributes to a better understanding of how the language-processing system builds long-distance dependency by interacting with the memory system.