Processing relative clauses across comprehension and production: similarities and differences

We compare the processing of relative clauses in comprehension (self-paced reading) and production (planned production). We manipulated the locality of two syntactic dependencies: filler-gap (subject vs object gap) and subject–verb (centre-embedded vs right-branched). The non-local filler-gap dependency resulted in a longer embedded predicate duration, across domains, consistent with memory-based accounts. For the non-local subject–verb dependency, we observe longer reading times at the main verb, but in production a greater likelihood and duration of a pause preceding the main verb. We argue that this result stems from the cost of computing the restriction, which manifests as a prosodic break. In the context of the subject–verb dependency manipulation, we also revisit the source of interpretation break-down in multiple centre-embedding. Generally, our findings imply that memory-based accounts are adequate for filler-gap, but not subject–verb, dependencies and production studies can aid in understanding complexity effects.