Abstract
This study explored the effects of semantic cues and comma insertion on the processing of garden-path sentences in Japanese. Pupil diameter was measured to monitor cognitive loads required in sentence processing. Participants read the Japanese relative-clause sentences with a temporary ambiguity with or without semantic information and/or a comma, which were expected to help readers to avoid garden paths. The results showed that pupil sizes showed marked dilations indicating increased cognitive load after the target word in the condition in which neither of the cues was absent, while either of these cues could reduce the pupil size. Interestingly we found a significant interaction between them, which indicated that readers used semantic information and a comma for sentence processing not independently. The semantic information dominated over comma, suggesting that language comprehension involves a complex process in which various sources of information at different levels interact with each other to disambiguate sentences.
