Proceedings of the Annual Meeting of the Cognitive Science Society

Two experiments investigated how task demands influence sentence processing mechanisms, as reflected in neural responses at the disambiguating word. Participants read garden-path sentences with late-closure ambiguity (e.g., While the man hunted the deer ran into the woods) and answered comprehension questions while their brainwaves were recorded. Experiment 1 used standard questions (e.g., Did the man hunt the deer?), while Experiment 2 used "explicit" questions (e.g., Did the sentence explicitly say that the man hunted the deer?) to reduce inference-based responses. Results showed a typical P600 effect for ambiguous sentences in Experiment 1, indicating syntactic reanalysis. In Experiment 2, responses showed an N400 followed by Sustained Frontal Negativity, suggesting a shift toward plausibility evaluation and increased processing load. The explicit questions appear to alter underlying sentence processing mechanisms, prompting more effortful resolution of interpretive conflict beyond initial syntactic reanalysis.