Refreshing Multi-Feature Objects in Visual Working Memory.

Abstract

"Thinking of" a representation in working memory is assumed to refresh its trace, boosting its accessibility. We previously demonstrated that think-of cues can be used to guide the refreshing of individual features in working memory (e.g., colors, orientations, words), with items refreshed more often being better reproduced in recall tasks. In the present study, we tested whether refreshing modulates the accessibility of multi-feature objects, contributing either to the maintenance of feature bindings or individual features. The "think-of" cues procedure was combined with a recognition task in Experiments 1 (N = 31) and 2 (N = 77) and with a dual-feature report task in Experiment 3 (N = 117). In all studies, participants encoded four colored shapes. During retention, a sequence of three think-of cues was presented, guiding refreshing of the memoranda 0, 1, or 2 times. In Experiments 1 and 2, a colored shape was presented for recognition (50% match and 50% mismatch). Critically, mismatch probes consisted of intrusions (new color with old shape or old color with new shape). Refreshing monotonically improved match-probe recognition, but not the rejection of intrusion probes. In Experiment 3, refreshing increased the correct recall of both features of the same object, whereas the probability of a single correct report remained constant. These results suggest that refreshing acted on the representation of the integrated object. Not refreshed objects, however, did not become more fragile to binding disruption, they mostly lost accessibility in an all-or-none fashion.