We examined the effect of interruption on reading to determine if discourse processing is susceptible to similarity-based interference. Participants read pairs of passages, either one before the other (in the continuous condition) or with the sentences of the two passages interleaved (in the interruption condition). In addition, the similarity of the types of passages (narrative or expository) in a pair was manipulated. Performance was measured with self-paced reading time of the sentences and with accuracy in answering comprehension questions. In two experiments, interruption slowed the reading of text sentences; this effect of interruption was greatest when the interrupting text was of the same style as the primary text (an interruption-similarity effect). We discuss these results with respect to current models of the role of working memory in discourse processing.Current memory models offer differing character-isations of the information that is maintained and manipulated in working memory during cognitive tasks, and of the structure of working memory itself. Our interest in this paper is in the nature of working memory underlying language comprehension, particularly as it handles interruption during reading. Different views of working memory in language processing lead to different predictions about how interruption should affect the process of reading comprehension.A great deal of research on text memory has demonstrated that some elements of a text (such as the semantic relationships among entities, or situational aspects) are remembered better (with more accuracy and over greater periods of time) than other elements (such as the exact wording of a particular sentence; Bransford & Franks, 1971;Sachs, 1967). This suggests that different types of information from a text are represented and organised differently in memory. Several researchers have described the processes by which text representations are created and maintained (Frederiksen, 1975;Graesser, 1981;Jarvella, 1979;Meyer, 1975). Kintsch and his colleagues (Kintsch & van Dijk, 1978; van Dijk & Kintsch, 1983; see also Kintsch, 1985 see also Kintsch, , 1994Kintsch, Welsch, Schmalhofer, & Zimny, 1990) have described three ways in which linguistic information is represented. The surface representation captures several aspects of the text (including lexical and syntactic information) verbatim, and is thus an exact mental representation of the text. The propositional or semantic representation captures the meaning of a text at both a local and a global level. Finally, the situational representation is further removed from the given text than the other two, and represents those aspects of prior knowledge that are triggered by the reading of the text; it is thus a representation based on schematic knowledge. The construction-integration model of discourse processing (Kintsch, 1988; see