Effects of Visual Working Memory (VWM) Load and Selective Attention on Recognition Memory for Unfamiliar Faces

When we look around, our subjective impression is of a highly detailed visual representation, which allows us to perceive changes in the identity and location of the objects and people around us. However, research has shown that this impression is misleading; the acuity and amplitude of visual sensory information varies across space and time and is subject to numerous post-perceptual filters. Among these, Visual Working Memory (VWM) is a limited capacity, transient store for visual information that supports the continuity of sensory experience. Selective visual attention protects VWM capacity by filtering relevant from irrelevant visual information during the encoding and maintenance of remembered objects. The aim of this thesis was to provide insights into the way in which capacity limits in VWM interact with selective attention to predict recognition accuracy for unfamiliar faces. In order to explore this issue, a Change detection paradigm was used to assess the relationship between memory load (set size) and d’ (an index of discriminability derived from Signal detection theory), while manipulating target-distractor similarity, mode of stimulus presentation, visual attention and eye movement. The results of six experiments yielded four key findings: (1) the sensitivity of recognition memory for unfamiliar faces is independently affected by the similarity and number of faces to remember, (2) stimulus-driven shifts of attention bias the allocation of VWM resources when multiple to-be-remembered (TBR) faces compete for selection, (3) the biasing signals that mediate competition between faces operate independently of the resolution of the information available to the observer, and (4) the sensitivity of recognition memory for unfamiliar faces is mediated by emotional valence. Taken together, these findings suggest that selective attention and VWM interact to mediate the accuracy of recognition memory for unfamiliar faces in a number of different situations.