Visual working memory can selectively reset a subset of its representations.

The visual working memory (VWM) resetting process is triggered when the mapping between an object in the environment and its corresponding VWM representation becomes irrelevant. Resetting involves discarding the no longer relevant representations, and encoding novel representations and mappings. We examined how resetting operates on VWM's contents. Specifically, we tested whether losing only part of the encoded mappings led to resetting all of the VWM representations. Subjects monitored moving polygons for an abrupt shape-change. Occasionally, a polygon separated into two halves that continued to move independently, making the original single mapping irrelevant. This loss of mapping triggered a resetting process, producing a performance cost: subjects missed shape-changes when they occurred during resetting, but not when the changes occurred before or after resetting. Critically, the cost was (1) specific to the separated item, (2) larger when more mappings were lost, and (3) unaffected by the set-size. This suggests that resetting is a "local" process: VWM removes only the representations whose mappings are lost.