Pictures help people to comprehend and remember texts. We report two experiments designed to test among several accounts of this facilitation. Students read texts describing four-step procedures in which the middle steps were described as occurring at the same time, although the verbal description of the steps was sequential. A mental representation of the procedure would have the middle steps equally strongly related to the preceding and succeeding steps (because the steps are performed simultaneously), whereas a mental representation of the text would have the middle step that was described first more closely related to the preceding step than the middle step described. After reading, strengths of the represented relationships between the steps were assessed. When the texts were accompanied by appropriate pictures, subjects tended to mentally represent the procedure. When the texts were presented alone or with pictures illustrating the order in which the steps were described in the text, subjects tended to mentally represent the text. We argue that these results disconfirm motivational, repitition, and dual code explanations of the facilitative effects of pictures. The results are consistent with a version of mental model theory that proposes that pictures help to build mental models of what the text is about.