Loss of visual working memory within seconds: The combined use of refreshable and non-refreshable features.

Abstract

We re-examine the role of time in the loss of information from working memory, the limited information accessible for cognitive tasks. The controversial issue of whether working memory deteriorates over time was investigated using arrays of unconventional visual characters. Each array was followed by a post-perceptual mask, a variable retention interval (RI), and a recognition probe character. Dramatic forgetting across an unfilled RI of up to 6 s was observed. Adding a distracting task during the RI (repetition, subtraction, or parity judgment using spoken digits) lowered the level of recall, but not increasingly so across RIs. Also, arrays of English letters were not forgotten during the RI unless distracting stimuli were included, in contrast to the finding for unconventional characters. The results suggest that unconventional visual items include some features inevitably lost over time. Attention-related processing, however, assists in the retention of other features, and of English letters. We identify important constraints for working memory theories and propose that an equilibrium between forgetting and reactivation holds, but only for elements that are not inevitably lost over time.

The impact of storage on processing: How is information maintained in working memory?

“…Correct rejections (i.e., correctly responding that there was no change) were analyzed by performing an analysis of variance on these percentages with RI duration (1,500 ms, 3,000 ms, or 6,000 ms) and presence of secondary task (no-task vs. parity) as within-subject factors. Like Ricker and Cowan (2010), we observed a significant effect of adding a secondary task, F(1, 26) ϭ 4.97, p Ͻ .05, p 2 ϭ .16, and a significant effect of the duration of RI, F(2, 52) ϭ 10.41, p Ͻ .001, p 2 ϭ .29, with no interaction (F Ͻ 1). Importantly, as we expected, a planned comparison showed that fonts were inevitably lost over time, even when attention was available for refreshing, as demonstrated by the significant effect of RI duration when there was no concurrent task, F(2, 26) ϭ 7.53, p Ͻ .01, with 84%, 70%, and 68% of observed correct rejections for delays of 1,500 ms, 3,000 ms, and 6,000 ms, respectively.…”

What limits working memory capacity?

“…Hence, at least for verbal memoranda, whether or not memory declines over a filled RI depends on the variability of distractor processing (see Figure 7). At the same time, some studies using visual or spatial memoranda have found that extending the duration of the RI impairs memory even in the absence of a concurrent processing task (B3; Lilienthal, Hale, & Myerson, 2014;Mercer & McKeown, 2014;Ricker & Cowan, 2010).…”

Control of information in working memory: Encoding and removal of distractors in the complex-span paradigm

“…First, there is strong evidence that at least verbal contents of working memory do not decay (Lewandowsky et al, 2009;Oberauer & Lewandowsky, 2013, 2014. Second, findings that are often cited in support of decay for non-verbal materials -a modest decline of accuracy over several seconds -imply a decay rate much too slow for clearing out working memory at the pace at which our stream of consciousness progresses (McKeown & Mercer, 2012;Mercer & Duffy, 2015;Mercer & McKeown, 2014;Ricker & Cowan, 2010;Ricker, Spiegel, & Cowan, 2014;Zhang & Luck, 2009). Working memory could not function as well as it does without removing outdated information, and the present experiments confirm a role for removal of distractors in keeping working memory working.…”