Does multisensory study benefit memory for pictures and sounds?

Studies have found a multisensory memory benefit: higher recognition accuracy for unimodal test items that were studied as bimodal items than for those studied as unimodal items. This is a surprising finding because the encoding specificity principle predicts that memory performance should be better with greater overlap between processing during study and test. We used Thelen, Talsma, and Murray's (2015) method who previously found a multisensory memory benefit. Items were presented as unimodal (picture or sound) or bimodal (picture and sound) items in a continuous recognition task in which only one modality was task-relevant. In four experiments we obtained little evidence for a difference in memory performance between items studied as unimodal or bimodal stimuli, but there was a benefit of study-test overlap in format if sound was the task-relevant modality. Task-induced attention for the irrelevant modality or response bias may have played a role in previous studies. We conclude that the multisensory memory benefit may not be a general finding, but rather one that is found only under conditions that induce participants to pay attention to the task-irrelevant modality.