Time resolves syntactic-semantic conflict in temporary semantic illusions: Evidence from role reversal sentences

Understanding why readers misinterpret role-reversed sentences like the waitress that the customer served (versus the customer that the waitress served) is important in understanding how readers process who does what to whom in sentences. In such sentence pairs, we infer that readers experience temporary illusions of plausibility from the absence of the usual N400 effect between the plausible and implausible verb served. A recent finding is that an N400 effect is observed if presentation of the verb is delayed. We first use ERPs to show that time alone rather than new information is sufficient to produce this delay effect. Our meta-analysis of published studies demonstrates a small but consistent effect of similar delays. Next, we distinguish between two accounts of the illusion addressing the delay effect: In one, the illusion results from conflict between syntactic and semantic cues (Sentence Gestalt (SG) model; Rabovsky et al., 2018), in the other, from the slow application of thematic roles (e.g., Liao et al., 2022). Using speeded lexical decisions, we demonstrate an immediate influence of thematic roles on verb processing, favouring the SG model. The role reversal effect on lexical decision times but not the N400 further supports the SG model because the model predicts a dissociation between preactivation of specific words (reflected in lexical decisions) versus sentence meaning (reflected in the N400). Together, the findings suggest that the rapid pace of reading can give rise to temporary illusions by preventing readers from resolving cue conflict rather than by omitting processing steps.