Prediction differs at sentence and discourse level: An event-related potential study

Abstract This study used event-related potentials (ERPs) to investigate how predicting upcoming words differ when contextual information used to generate the prediction is from the immediately preceding sentence context versus an earlier discourse context. Four-sentence discourses were presented to participants, with the critical words in the last sentences, either predictable or unpredictable based on sentence- or discourse-level contextual information. At the sentence level, the crucial contextual information for prediction was provided by the last sentence, where the critical word was embedded (e.g., Xiaoyu came to the living room. She made a cup of lemon tea. Then she sat down in a chair. She opened a box /an album to look at the pictures. ), and at the discourse level by the first sentence (e.g., Xiaoyu took out a box /an album . She made a cup of lemon tea. Then she sat down in a chair. She leisurely looked at the pictures. ). Results showed reduced N400 for predictable words compared to unpredictable counterparts at sentence and discourse levels and also a post-N400 positivity effect of predictability at sentence level. This suggests that both sentence- and discourse-level semantic information help readers predict upcoming words, but supportive sentence context more than discourse context.