Short-Term Forgetting and the Articulatory Loop

Abstract

Two experiments explored the role of subvocal articulatory rehearsal in the Peterson short-term forgetting task. In the first of these, subjects recalled consonant trigrams after an interval of 0, 5 or 15 s during which they either counted backwards in threes, suppressed articulation by continuously uttering the word “the”, or in a third control condition continuously tapped on the table. While counting backwards caused the usual dramatic forgetting, tapping caused no forgetting, and articulatory suppression only minimal forgetting at the longest delay. A second study used the same procedure but included only two conditions, articulatory suppression during the retention interval and articulatory suppression during both input and retention. Neither showed evidence of forgetting over the 15 s delay. These results suggest that covert speech is not necessary for rehearsal in short-term verbal memory. As such they call for a re-evaluation of the nature and function of rehearsal.

What limits working memory capacity?

“…Here we are not concerned with the debate between proponents of discrete slots and proponents of continuous resources (for a systematic comparison in the visual domain see van den Berg, Awh, & Ma, 2014), and instead treat both positions as members of the family of resource explanations of WM capacity. Because the assumption of continuously divisible resources is more flexible than the discrete-resource notion, in the following we focus on the hypothesis of continuous limited resources.…”

“…Resource models have been very successful in quantitatively accounting for the effect of set size on the precision of recall of visual features (Bays, 2014;Ma et al, 2014;van den Berg et al, 2014).…”

“…Subvocal articulatory rehearsal can be prevented through articulatory suppression -asking participants to repeat a simple utterance continuously. Experiments varying the duration of a retention interval during which participants engaged in articulatory suppression found no decline of memory with longer retention intervals (B2; Humphreys et al, 2010;Lewandowsky et al, 2004;Longoni, Richardson, & Aiello, 1993;Phaf & Wolters, 1993;Vallar & Baddeley, 1982). Refreshing can be prevented by simple binary decision tasks that engage central attention (Barrouillet et al, 2007).…”

“…Speaking an irrelevant word or syllable aloud impairs memory for verbal lists, but it does not matter for how long the same utterance is repeated (Humphreys et al, 2010;Longoni et al, 1993;Phaf & Wolters, 1993;Vallar & Baddeley, 1982). Likewise, making simple binary decisions impairs serial recall of verbal lists, but the number of such decisions to be carried out at a constant rate has little impact on memory .…”

The effects of processing time and processing rate on forgetting in working memory: Testing four models of the complex span paradigm

“…The possibility of two forms of rehearsal was anticipated early in the development of working memory research (Vallar & Baddeley, 1982), but the evidence for it was not compelling, and it was therefore largely neglected. One exception is the distinction made between rehearsal and refreshing in the MEM framework of Johnson (1992).…”