On the Right Track? Investigating the Effect of Path Characteristics on Visuospatial Bootstrapping in Verbal Serial Recall

Abstract

Visuospatial bootstrapping (VSB) occurs when memory for verbal material is enhanced via association with meaningful visuospatial information. Sequences of digits are visually presented either in the center of the screen or within a keypad layout in which the digits may be arranged identically to familiar pin pad and mobile phone layouts, or randomly. Recall is consistently higher when digits are presented in the familiar layout. This "bootstrapping" could involve primarily long-term knowledge of the layout, primarily short-term memory of the unique spatial path, or may depend on both. We manipulated the path complexity of sequences to test whether the VSB effect depends on the quality of spatial representations in conjunction with the familiarity of the spatial layout in two experiments. We consistently observed both VSB effects and path complexity effects on verbal serial recall, but never observed any interaction between these factors, even when articulatory suppression was imposed. Analysis of recall by serial position revealed that the VSB effect was focused on the end-of-list items. Our finding of pervasive path complexity effects on verbal serial recall suggests incidental encoding of spatial path occurs during visually-presented verbal tasks regardless of layout familiarity, confirming that spatial factors can affect verbal recall, but ruling out the notion that incidental spatial paths are uniquely and voluntarily encoded with familiar layouts.

Visuospatial bootstrapping: spatialized displays enhance digit and nonword sequence learning

“…The replication of this effect in Experiment 2 using nonwords demonstrated that the bootstrapping effect on learning was not limited to numeric or single-character stimuli. Previous research [15][16][17][18][19][20][21][22][23] has indicated that spatialized information at presentation can facilitate immediate serial recall; these experiments extend that finding to sequence learning.…”

“…Evidence for or against a bootstrapping effect in immediate serial recall on the very first presentation was far from compelling. Numerous previous studies [16][17][18][19][20][21][22][23] have replicated bootstrapping effects in STM tasks, so it is worth considering what may have been the reason that the effect was not readily apparent in the current study. One plausible explanation is simply that the task of recalling a 12-item sequence in immediate recall with no prior knowledge of the sequence is too difficult, an explanation that is entirely consistent with the very low recall performance in later sequence positions.…”

“…Bootstrapping effects have been replicated frequently. [15][16][17][18][19][20][21][22][23] VSB has been interpreted in terms of the multicomponent [24][25][26][27] model of WM as occurring when a visual presentation contains information that can be used to support-"bootstrap"the activities of phonological STM. Verbal interference 17 and interference to set-switching processes 19 do not seem to reduce the bootstrapping effect, while spatial interference is associated with its absence.…”

“…Typically, performance is improved with keypad displays. Bootstrapping effects have been replicated frequently 15–23 …”

Visuospatial bootstrapping: Binding useful visuospatial information during verbal working memory encoding does not require set-shifting executive resources

“…The pattern is named for the fact that visuospatial processes appear able to boost—bootstrap—verbal recall performance when incidental visuospatial information is available at encoding. Bootstrapping benefits considerably from familiarity of the participant with the keypad display being used, leading to the conclusion that it typically involves a long-term memory (LTM) component (Darling, Allen, Havelka, Campbell, & Rattray, 2012), though there is now evidence that some spatial support to verbal memory is possible without a connection to long-term knowledge (Allan, Morey, Darling, Allen, & Havelka, 2017). Allen, Havelka, Falcon, Evans, and Darling (2015) administered tasks aimed at causing verbal and spatial suppression during presentation of digits and found that bootstrapping persisted under suppression of verbal working memory but was completely abolished under spatial load during encoding (though not recall), demonstrating that bootstrapping recruited spatial working memory resources but did not recruit verbal resources beyond those used in the single-item condition, and that these resources were recruited during encoding.…”