Target distinctiveness modulates resource allocation in visual working memory for faces: implications for eyewitness face identification

Visual working memory (VWM) is a limited-capacity resource for the temporary storage of visual information (Cowan, 2001). Selective visual attention can protect VWM capacity by filtering relevant from irrelevant information during encoding or maintenance (Griffin & Nobre, 2003).The aim of the current study was to investigate whether target distinctiveness bias the allocation of visual working memory (VWM) resources during the encoding of unfamiliar faces. The results indicate that VWM capacity for unfamiliar faces is poor and declines as a function of the number of faces in the display (load). When one of the faces in the display was made distinct (i.e. by adding a tattoo to it), recall accuracy was independent of load, suggesting bottom-up attentional mechanisms protect against competition for limited VWM resources. These findings have a number of implications in real-world eyewitness scenarios. For example, the accuracy of eyewitness identification is likely to depend upon the number of individuals at the crime scene and differences in their salient visual characteristics.