The fidelity of visual memory for faces and non-face objects

The fidelity of visual working memory was assessed for faces and non-face objects. In two experiments, four levels of memory load (1, 2, 3, or 4 items) were combined with four perceptual distances between probe and study items, with maximum item confusability occurring for the minimum memory load. Under these conditions, recognition memory for multiple faces exceeded that of a single face. This result was primarily due to the higher false alarm rates for faces than non-face objects, even though the two classes of stimuli had been matched for perceptual discriminability. Control experiments revealed that this counterintuitive result emerged only for old-new recognition choices based on near-threshold image differences. For non-face objects, instead, recognition performance decreased with increasing memory load. It is speculated that the low memorial discriminability of the transient properties of a face may serve the purpose of enhancing recognition at the individual-exemplar level.