The picture complexity effect: another list composition paradox

List composition effects refer to the findings in which a given memory phenomenon shows discrepant patterns across different list designs (i.e., mixed or pure lists). These effects have typically been reported with verbal materials (e.g., word lists, paired associates, sentences); much less research has examined whether these effects generalize to pictorial materials. In 3 experiments, we investigated whether list composition effects extend to the picture complexity effect, the finding that complex pictures are sometimes better recalled than simple pictures. Our results consistently indicated superior recall for complex pictures relative to simple pictures in mixed but not pure lists. We also examined 3 prominent theoretical accounts that have been proposed to explain list composition effects with verbal materials: (a) the item-order framework (Experiment 1), (b) the retrieval distinctiveness hypothesis (Experiment 2), and (c) the attention-borrowing theory (Experiment 3). Our findings indicated that the attention-borrowing theory is a viable candidate explanation for list composition effects with pictorial materials.