Increasing the functional capacity of visual short-term memory through attention and long-term memory

Abstract

Goals: Numerous laboratories have reported that the capacity of visual short-term memory (VSTM) is about 4 items or 6 locations. The few reports of changes in this capacity have reported decreases in capacity in association with VSTM for complex items. We report that the functional capacity of spatial VSTM can be increased through the acquisition of long-term memory traces. Methods and Results: Long-term memory was manipulated by repeating some of the displays over the course of a 1-hr experiment. This effect only occurred when the repeated display was associated with an invariant target location, suggesting that long-term memory modulates VSTM via attention. An interference task decreased performance on the “new” but not “old” displays. Conclusions: These findings suggest that the capacity of VSTM can be flexibly manipulated by the incidental acquisition of long-term memory traces. In addition, these finding point to reciprocal modulatory interactions between VSTM, long-term memory, and attention.