The ability to flexibly allocate attention to goal-relevant information is pivotal for the completion of high-level cognitive processes. For instance, in comprehending illustrated texts, the reader permanently has to switch the attentional focus between the text and the corresponding picture in order to extract relevant information from both sources. Thus, the hypothesis was tested that individuals with a lower switching capacity exhibit a decreased performance in tasks that require the flexible switch of attention between two external representations. Participants read an illustrated text and answered questions that either required the extraction of information from the text alone or from the text and the corresponding illustration. In addition, a switching task was accomplished. Results indicate that a lower switching capacity resulted in a poorer performance in those tasks that required the extraction of relevant information from two sources.