Discourse processing extends language comprehension beyond the sentence to examine how we understand connected text and conversation. Understanding a story, following a lecture, or participating in a conversation requires building a coherent mental model that integrates information across sentences, draws inferences, tracks referents, and maintains thematic coherence. These processes go well beyond syntax and semantics to engage world knowledge, pragmatic reasoning, and memory.
Situation Models
Van Dijk and Kintsch (1983) proposed that discourse comprehension produces representations at three levels: the surface level (exact words and syntax), the textbase (the propositions explicitly stated), and the situation model (a mental model of the described situation). The situation model integrates text information with the reader's world knowledge to represent the characters, spatial setting, temporal sequence, causal relationships, and emotional content of the discourse. It is the situation model that supports deep understanding and long-term memory for text content.
Inference Generation
Much of what we understand from discourse is not explicitly stated but must be inferred. Bridging inferences connect adjacent sentences ("Mary threw a ball at the window. The glass shattered" requires inferring that the ball broke the window). Elaborative inferences embellish the representation with likely details. Causal inferences establish cause-effect relationships. Predictive inferences anticipate upcoming events. The extent and timing of inference generation during reading has been intensively studied using reading time and ERP measures.
Coherent discourse requires both cohesion (linguistic devices connecting sentences: pronouns, connectives, repeated words) and coherence (conceptual connections: causal, temporal, and logical relationships). Disrupting cohesion (removing connectives) or coherence (scrambling sentence order) impairs comprehension and memory, demonstrating that discourse processing actively constructs a connected representation rather than simply concatenating individual sentence meanings.