The voluntary utilization of visual working memory.

While a vast amount of research has focused on understanding the capacity limits of visual working memory (VWM), little is known about how VWM resources are employed in unforced behavior and how they correlate with individual capacity constraints. We present a novel, openly available, and easy-to-administer paradigm enabling participants to freely utilize their VWM capacity. Participants had to reconstruct an array of colored squares. In each trial, they were allowed to alternate between the memory array and the reconstruction screen as many times as they wished, each time choosing how many items to reconstruct. This approach allowed us to estimate the number of utilized items, as well as the accuracy of the reconstruction. In addition, VWM capacity was measured using a change detection task. In two experiments, we show that participants tend to under-utilize their VWM resources, performing well below their capacity limits. Surprisingly, while the extent to which participants utilized their VWM was highly reliable, it was uncorrelated with VWM capacity, suggesting that VWM utilization is limited due to strategic considerations rather than capacity limits.