2. Theoretical Approaches to Discourse Processing

Several theories of discourse processing have been proposed over the past two decades. These theories differ in the cognitive mechanisms that are evoked to explain how discourse is understood, but they agree on several issues:

1. Comprehension of a discourse leads to a mental representation of that discourse.

2. Comprehenders routinely update their mental representations. Updating involves the integration of new information into their existing representation of the discourse.

3. Comprehenders draw at least some inferences during the comprehension of discourse. These inferences help to maintain discourse coherence at both global and local levels.

4. Some of the information from the discourse remains highly active in memory (i.e., in the foreground of the discourse), whereas other information is less active in memory (i.e., in the background of the discourse). Whether a given element is in the foreground or the background of the discourse depends on the current focus of the discourse.

5. The comprehension of a discourse can be affected by a number of variables, such as the genre of the discourse being processed and the comprehender’s goals for understanding the discourse.

These themes of discourse-processing research have been integrated into and explained by a number of individual theories.

1.2.1. Construction-Integration Model

The construction-integration model was proposed by Kintsch (1988). This model proposes that discourse is comprehended in two iterative stages. In the construction stage, the incoming text base, which is a representation of the content of the discourse but not of the actual words and phrases in the text) enters working memory; in working memory, the text base retrieves potentially relevant information from long-term memory. This stage of processing can be described as ballistic: it happens quickly and automatically. During the integration stage, the comprehension system begins to integrate the new information with the previously existing model of the discourse. The integration stage is comparatively slow and resource consuming, as the comprehension system pares down the information activated in the construction stage and integrates only the information that is most relevant to the present situation into the model of the discourse. The resulting representation is called a ‘situation model.’

1.2.2. Structure-Building Framework

The structure-building framework was outlined by Gernsbacher (1990). The theory proposes that discourse comprehension proceeds by building mental representations of the information presented in the discourse, with the initial process in building a structure called ‘laying a foundation.’ The foundation of the structure is based around the characters and events initially presented in the discourse. When new information is presented, it can either be mapped to the existing structure (i.e., it is attached to the existing structure), or it can prompt the comprehension system to shift to a new structure (i.e., the comprehender lays the foundation for a new structure). Finally, some information in the structure can be enhanced, made more available for further processing, whereas other information can be suppressed, made temporarily unavailable for further processing.