Abstract
Competition between visually presented stimuli is associated with reduced neural firing, longer reaction time and reduced BOLD response. It is not known whether the effects of competition extend to working memory (WM), nor whether competition represents a common limiting-factor, compromising both WM performance in the absence of distraction, as well as effective distractor exclusion. Here we measured WM precision for an item placed with small or large spatial separation from another item to be remembered, or from a distractor. In both cases, WM precision was significantly reduced for small relative to large spatial separation. This indicates that the effects of competition extend to WM precision, and identifies competition as a potential common mechanism affecting WM regardless of whether the two items being encoded are both to be remembered, or whether one is a distractor. Such a mechanism is a potential basis for the association identified between distractor exclusion and WM in the absence of distraction.