Searching for serial refreshing in working memory: Using response times to track the content of the focus of attention over time

Abstract

One popular idea is that, to support maintenance of a set of elements over brief periods of time, the focus of attention rotates among the different elements thereby serially refreshing the content of Working Memory (WM). In the research reported here, probe letters were presented between to-be-remembered letters. Response times to these probes were used to infer the status of the different items in WM. If the focus of attention cycles from one item to the next, its content should be different at different points in time and this should be reflected in a change in the response time patterns over time. Across a set of four experiments, we demonstrate a striking pattern of invariance in the response time patterns over time, suggesting that either the content of the focus of attention did not change over time or that response times cannot be used to infer the content of the focus of attention. We discuss how this pattern constrains models of WM, attention, and human information processing.

Benchmarks for models of short-term and working memory.

“…For example, by systematically varying the time at which participants were asked to respond, Wickelgren, Corbett, and Dosher (1980) found that participants were sooner able to match the most recent study item to the test item than study items presented earlier in the list ( Figure A1; for a more comprehensive review see McElree, 2006). This finding qualifies as benchmark because of its replicability, and because it plays an important role in the case for a focus of attention in working memory (McElree, 2006;Oberauer & Hein, 2012;Vergauwe et al, 2016). Because it has limited generality, and qualifies benchmark 3.3.1, we assign it a low priority (C), although survey participants tended more towards a B rating (7/15).…”

What is attentional refreshing in working memory?

“…Recent studies have tested the serial refreshing hypothesis according to which spontaneous refreshing of a memory list operates serially, with the focus of attention cycling from one item to the next . An obvious way of implementing serial refreshing consists of refreshing the items of a memory list in a cumulative, forward order, that is, in the order of presentation starting with the first‐presented memory item, followed by the second‐presented memory item, etc.…”

Attentional refreshing of information in working memory: Increased immediate accessibility of just-refreshed representations

“…One possibility might be that the presence of a probe, in between each letter presentation, in the probe-span task used by Vergauwe et al (2016) might have discouraged the spontaneous use of refreshing, and/or that including a condition of instructed refreshing in the current study might have encouraged the spontaneous use of refreshing, even in the conditions without instructions 3 . The observations that people can refresh items when they are instructed to do so and that people spontaneously refresh in experiments that also include instructed-refreshing conditions do not necessarily imply that refreshing occurs spontaneously in all situations.…”

“…We applied the same performance-based exclusions as in the Vergauwe et al (2016) study, to keep things consistent between studies. First, we discarded the data of participants whose average accuracy of their response to the probes fell below 55% (1, 0, 0, 0, and 4 participants in Experiments 1 through 5, respectively).…”