Semantic and pragmatic processes in the comprehension of negation: An event related potential study of negative polarity sensitivity

• An ERP study on the processing of different types of negation.
• Both explicit and implicit negation are processed rapidly online.
• But explicit and implicit negation showed different P600 patterns.
• Implicit negation evokes additional pragmatic processing cost.

Most previous studies on negation have generally only focused on sentential negation (not), but the time course of processing negative meaning from different sources remains poorly understood. In an ERP study (Experiment 1), we make use of the negation-sensitivity of negative polarity items (NPIs) and examine the time course of processing different kinds of negation. Four kinds of NPI-licensing environments were examined: the negative determiner no, the negative determiner few, the focus marker only, and emotive predicates (e.g., surprised). While the first three contribute a negative meaning via semantic assertion (explicit negation), the last gives rise to a pragmatic negative inference via non-asserted content (implicit negation). Under all these environments, an NPI elicited a smaller N400 compared to an unlicensed NPI, suggesting that negation, regardless of its source, is rapidly computed online. However, we also observed that explicit negative meaning (i.e., semantic, as contributed in the assertion) and implicit negative meaning (contributed by pragmatic inferences) were integrated into the grammatical representation in different ways, leading to a difference in the P600, and calling for a separation of semantic and pragmatic integration during sentence processing (and NPI licensing). The qualitative differences between these conditions were also replicated in a self-paced reading study (Experiment 2).