Syntax and processing in Seediq: an event-related potential study

In many languages with subject-before-object as a syntactically basic word order, transitive sentences in which the subject precedes the object have been reported to have a processing advantage over those in which the subject follows the object in sentence comprehension. Three sources can be considered to account for this advantage, namely, syntactic complexity (filler-gap dependency), conceptual accessibility (the order of thematic roles), and pragmatic requirement. To examine the effect of these factors on the processing of simple transitive sentences, the present study conducted two event-related potential experiments in Seediq, an Austronesian language spoken in Taiwan, by manipulating word orders (basic VOS vs. non-basic SVO), the order of thematic roles (actor vs. goal voice), and discourse factors (presence/absence of visual context). The results showed that, compared to VOS, SVO incurred a greater processing load (reflected by a P600) when there was no supportive context, irrespective of voice alternation; however, SVO did not incur a greater processing load when there was supportive context and the discourse requirement was satisfied. We interpreted these results as evidence that the processing difficulty of the non-basic word order in Seediq is associated with a discourse-level processing difficulty.