[Effects of repetition and dual-task on output monitoring errors]

We investigated output-monitoring errors in a modified source-monitoring paradigm. Unlike the traditional paradigm that involves two phases, learning and monitoring, the modified paradigm involves three phases, learning, enactment, and monitoring. Three experiments produced two major findings. First, compared with the traditional paradigm, the modified paradigm produced fewer monitoring errors. Second, performing a dual-task during the enactment phase increased monitoring errors for the items that participants repeatedly enacted during the learning phase. In contrast, performing a dual-task during the learning phase did not influence monitoring errors. It only decreased the number of items that were enacted during the enactment phase. We concluded that monitoring errors are more likely to occur (a) when the modality of items matches between the learning and enactment phases (i.e., items are enacted during both phases), and (b) when a dual-task increases processing demands during the enactment phase.