Maintaining binding in working memory: Comparing the effects of intentional goals and incidental affordances

Much research on memory for binding depends on incidental measures. However, if encoding associations benefits from conscious attention, then incidental measures of binding memory might not yield a sufficient understanding of how binding is accomplished. Memory for letters and spatial locations was compared in three within-participants tasks, one in which binding was not afforded by stimulus presentation, one in which incidental binding was possible, and one in which binding was explicitly to be remembered. Some evidence for incidental binding was observed, but unique benefits of explicit binding instructions included preserved discrimination as set size increased and drastic reduction in false alarms to lures that included a new spatial location and an old letter. This suggests that substantial cognitive benefits, including enhanced memory for features themselves, might occur through intentional binding, and that incidental measures of binding might not reflect these advantages. (C) 2011 Elsevier Inc. All rights reserved

The Color-Sharing Bonus:Roles of Perceptual Organization and Attentive Processes in Visual Working Memory

Color repetitions in a visual scene boost memory for its elements, a phenomenon known as the color-sharing effect. This may occur because improved perceptual organization reduces information load or because the repetitions capture attention. The implications of these explanations differ drastically for both the theoretical meaning of this effect and its potential value for applications in design of visual materials. If repetitions capture attention to the exclusion of other details, then use of repetition in visual displays should be confined to emphasized details, but if repetitions reduce the load of the display, designers can assume that the nonrepeated information is also more likely to be attended and remembered. We manipulated the availability of general attention during a visual memory task by comparing groups of participants engaged in meaningless speech or attention-demanding continuous arithmetic. We also tracked eye movements as an implicit indicator of selective attention. Estimated memory capacity was always higher when color duplicates were tested, and under full attention conditions this bonus spilled over to the unique colors too. Analyses of gazes showed that with full attention, participants tended to glance earlier at duplicate colors during stimulus presentation but looked more at unique colors during the retention interval. This pattern of results suggests that the color-sharing bonus reflects efficient perceptual organization of the display based on the presence of repetitions, and possibly strategic attention allocation when attention is available.<br/

Impact of memory load on processing diminishes rapidly during retention in a complex span paradigm

Previous work with complex memory span tasks, in which simple choice decisions are imposed between presentations of to-be-remembered items, shows that these secondary tasks reduce memory span. It is less clear how reconfiguring and maintaining various amounts of information affects decision speeds. We introduced preliminary “lead-in” decisions and postencoding “lead-out” decisions to isolate potential influences of reconfiguration and maintenance on decision speeds. Compared with preliminary lead-in choice responses, the response associated with the first memory item slowed substantially. As the list accumulated, decision responses slowed even more. After presentation of the list was complete, decision responses sped rapidly: within a few seconds, decisions were at least as fast as when remembering a single item. These patterns appeared consistently regardless of differences in list length (4, 5, 6, or 7 to-be-remembered items) and response mode (spoken, selection via mouse). This pattern of findings is inconsistent with the idea that merely holding information in mind conflicts with attention-demanding decision tasks. Instead, it is likely that reconfiguring memory items for responding is the source of conflict between memory and processing in complex span tasks

The developing impact of verbal labels on visual memories in children

The capacity limitations of visual working memory may be bypassed by verbal labeling. In adults, labeling increases estimates of both quantity and quality of visual working memory. However, we do not know when children begin to use labeling and whether labeling similarly benefits visual memories of children under and over age 7. We assessed whether children benefit from prompted and spontaneous labeling opportunities, examining how labeling affects the storage of categorical (prototypical) and continuous (fine-grained) color information. Participants memorized colored candies for a continuous reproduction test either while remaining silent, labeling the colors aloud, or saying irrelevant syllables (discouraging verbal labeling). Mixture modeling confirmed that both categorical and continuous representations increased with age. Our labeling manipulation showed that spontaneous labeling increased with age. For the youngest children, prompted labeling especially boosted categorical memory, whereas labeling benefited categorical and continuous memory similarly in the older age groups

Hanging on the telephone: Maintaining visuospatial bootstrapping over time in working memory

Visuospatial bootstrapping (VSB) refers to the phenomenon in which performance on a verbal working memory task can be enhanced by presenting the verbal material within a familiar visuospatial configuration. This effect is part of a broader literature concerning how working memory is influenced by use of multimodal codes and contributions from long-term memory. The present study aimed to establish whether the VSB effect extends over a brief (5-s) delay period, and to explore the possible mechanisms operating during retention. The VSB effect, as indicated by a verbal recall advantage for digit sequences presented within a familiar visuospatial configuration (modelled on the T-9 keypad) relative to a single-location display, was observed across four experiments. The presence and size of this effect changed with the type of concurrent task activity applied during the delay. Articulatory suppression (Experiment 1) increased the visuospatial display advantage, while spatial tapping (Experiment 2) and a visuospatial judgment task (Experiment 3) both removed it. Finally, manipulation of the attentional demands placed by a verbal task also reduced (but did not abolish) this effect (Experiment 4). This pattern of findings demonstrates how provision of familiar visuospatial information at encoding can continue to support verbal working memory over time, with varying demands on modality-specific and general processing resources

Goal-neglect links Stroop interference with working memory capacity

Relationships between Stroop interference and working memory capacity may reflect individual differences in resolving conflict, susceptibility to goal neglect, or both of these factors. We compared relationships between working memory capacity and three Stroop tasks: a classic, printed color-word Stroop task, a cross-modal Stroop, and a new version of cross-modal Stroop with a concurrent auditory monitoring component. Each of these tasks showed evidence of interference between the semantic meaning of the color word and the to-be-named color, suggesting these tasks each require resolution of interference. However, only Stroop interference in the print-based task with high proportions of congruent trials correlated significantly with working memory capacity. This evidence suggests that the relationships observed between Stroop interference and working memory capacity are primarily driven by individual differences in the propensity to actively maintain a goal. (C) 2012 Elsevier B.V. All rights reserved