Spatial short-term memory assists in maintaining occluded objects.

We examined the role of spatial short-term memory (SSTM) in maintaining the hidden portions of occluded objects. We measured the degree of maintenance by asking participants to perform an object-based attention task on occluded objects while maintaining four locations in SSTM. SSTM did not interfere with object-based selection generally. Maintenance of occluded portions of objects was prevented when four locations were held in SSTM and these locations did not overlap with the locations of occluded objects. Importantly, when the observers remembered locations that overlapped with the occluded regions of objects, the occluded objects were maintained behind the occluder. These results suggest that SSTM participates in maintaining the occluded sections of objects.