A two-level hierarchical framework of visual short-term memory

Abstract

Over the last couple of decades, a vast amount of research has been dedicated to understanding the nature and the architecture of visual short-term memory (VSTM), the mechanism by which currently relevant visual information is maintained. According to discrete-capacity models, VSTM is constrained by a limited number of discrete representations held simultaneously. In contrast, shared-resource models regard VSTM as limited in resources, which can be distributed flexibly between varying numbers of representations; and a new interference model posits that capacity is limited by interference among items. In this article, we begin by reviewing benchmark findings regarding the debate over VSTM limitations, focusing on whether VSTM storage is all-or-none and on whether object complexity affects capacity. After that, we put forward a hybrid framework of VSTM architecture, arguing that this system is composed of a two-level hierarchy of memory stores, each containing a different set of representations: (1) perceptual memory, a resourcelike level containing analog automatically formed representations of visual stimuli in varying degrees of activation, and (2) visual working memory, in which a subset of three to four items from perceptual memory are bound to conceptual representations and to their locations, thus conveying discrete (digital/symbolic) information which appears quantized. While perceptual memory has a large capacity and is relatively nonselective, visual working memory is restricted in the number of items that can be maintained simultaneously, and its content is regulated by a gating mechanism.

Event-based encoding of biological motion and location in visual working memory

“…The feature integration theory (FIT) holds that the location offers a spatial map to which features are attached and are hence integrated to form objects (Treisman & Gelade, 1980). Treisman & Zhang (2006) extended the view of FIT from perception to VWM, positing that locations provide the reference frame for bindings that are formed between features, which has been integrated into recent theories/models of VWM (e.g., Xu & Chun, 2009; Yatziv & Kessler, 2018). Empirical studies also supported a privileged role of location in the initial processing and retention of visual displays.…”

Current controversies in the cognitive science of short-term memory

“…There is some evidence, for example, for a form of visual sensory memory with somewhat smaller capacity but greater duration (up to several seconds) than iconic memory dubbed Fragile Visual Short-Term Memory (fVSTM) [8]). Some have suggested that this apparent new store can be explained away via a more complex account of differences in attentional processing of items in iconic memory [9], while others have suggested that fVSTM and sensory memory should be considered parts of an integrated system of 'perceptual memory' [10].…”