Temporal dynamics of encoding, storage, and reallocation of visual working memory

Abstract

The process of encoding a visual scene into working memory has previously been studied using binary measures of recall. Here, we examine the temporal evolution of memory resolution, based on observers' ability to reproduce the orientations of objects presented in brief, masked displays. Recall precision was accurately described by the interaction of two independent constraints: an encoding limit that determines the maximum rate at which information can be transferred into memory and a separate storage limit that determines the maximum fidelity with which information can be maintained. Recall variability decreased incrementally with time, consistent with a parallel encoding process in which visual information from multiple objects accumulates simultaneously in working memory. No evidence was observed for a limit on the number of items stored. Cuing one display item with a brief flash led to rapid development of a recall advantage for that item. This advantage was short-lived if the cue was simply a salient visual event but was maintained if it indicated an object of particular relevance to the task. These cuing effects were observed even for items that had already been encoded into memory, indicating that limited memory resources can be rapidly reallocated to prioritize salient or goal-relevant information.

Exhausting attentional tracking resources with a single fast-moving object

“…Here we studied only the tracking of object positions over time, but it is possible the findings apply to multiple object attention more generally. If so, this resource may also gate the entry of information into visual working memory, yielding phenomena such as the trade-off between number of items and precision of working memory (Bays et al, 2011).…”

“…A similar theoretical debate has arisen regarding the processing that encodes information into working memory, with some authors proposing a flexible resource (Shibuya & Bundesen, 1988;Bays et al 2011;Alvarez & Cavanagh 2004;Wilken & Ma, 2004) and others suggesting a fixed limit or number of slots (Cowan, 2001;Pashler, 1988;Luck & Vogel, 1997).…”

Beyond a mask and against the bottleneck: Retroactive dual-task interference during working memory consolidation of a masked visual target.

“…After all, if it were true that consolidation is interrupted by a mask and that the consolidation of a single letter takes only 25 ms, then this would entail that a variety of theories of the attentional blink are incorrect in assuming that this effect reflects the time course of WMC. 1 Conversely, if it were true that WMC can continue for several hundred milliseconds after a mask, then this would entail that researchers can no longer assume that backward masking can be used as a means to assess or restrict the duration of consolidation, as has been done in many previous empirical and theoretical studies (e.g., Bays et al, 2011;Bundesen, 1990;Fuller et al, 2005;Gegenfurtner & Sperling, 1993;Saults & Cowan, 2007;Shibuya & Bundesen, 1988;Sun et al, 2011;Todd et al, 2011;Vogel et al, 2006;Woodman & Vogel, 2005;Wutz & Melcher, 2013;Zhang & Luck, 2008). 2 The goal of the current study was to adjudicate between the opposing perspectives on the dynamics of WMC.…”

Fragile associations coexist with robust memories for precise details in long-term memory.

“…To characterize the contributions of imprecision, misassociation, and complete forgetting of memories during learning and forgetting, we analyzed subjects' responses with a mixture model, similar to that used in Bays, Gorgoraptis, Wee, Marshall, and Husain (2011; Figure 3; see Appendix A for technical details). Under this model, each response is either an imprecise report of the target item, an imprecise report of one of the other items (a misassociation), or a random guess.…”