A Computational Model of Working Memory Integrating Time-Based Decay and Interference

Abstract

There is still a strong debate in the working memory literature about the cause of forgetting, with many articles providing evidence for the existence of temporal decay and as many publications providing evidence compatible with interference being the only mechanism involved in forgetting. In order to reconcile the two views, this article describes TBRS∗-I (for Time-Based Resource-Sharing∗-Interference), a computational model of working memory which incorporates an interference-based mechanism to the decay-based implementation TBRS∗ within the TBRS theoretical framework. At encoding, memoranda are associated to their context, namely their position in the list. Temporal decay decreases the strength of these associations, but a refreshing process may reactivate it during free time. Distractors may alter the distributed representation of memoranda but refreshing can restore them based on the long-term memory representations. Refreshing is therefore twofold: reactivation plus restoration, each one counteracting the detrimental time-based and interference-based decays, respectively. Two types of interference are implemented: interference by confusion which depends on the degree of overlap between memoranda and distractors and interference by superposition which depends on the similarity between them. TBRS∗-I was tested on six benchmark findings on retention-interval and distractor-processing effects by means of millions of simulations testing the effects of seven factors on memory performance: the number of memoranda, the duration of distractor attentional capture, the duration of free time, the number of distractors, the amount of overlap between memoranda and distractors, the similarity between memoranda and distractors and the homogeneity of distractors (all identical or all distinct). TBRS∗-I replicated classical effects and proved to be a suitable hybrid model integrating both interference and time-based decay. The article also discusses the compatibility of TBRS∗-I with a unitary or dual view of memory and the issue of integrating time and interference in a single model. Computer codes and data are available at https://osf.io/65sna/.

Working memory and information processing in ADHD: Evidence for directionality of effects.

“…This interaction was detected for the information processing speed and working memory manipulations, but only when the manipulated process was the outcome (i.e., no cross-domain interaction effects that would suggest that impairments in one process are attributable to impairments in the other). These findings collectively indicate that (a) working memory deficits in ADHD cannot be explained by more basic task demands associated with the rate at which information is encoded, (b) the ADHD group’s reduced information processing speed may be most detectable under conditions that allow relatively fast information processing speed and place relatively low demands on working memory (despite being relatively unaffected by changes in inhibition demands; Fosco, Kofler, Alderson, et al, 2019), whereas conditions that evoke slower information processing speed/higher working memory demands differentially affect non-ADHD children who then perform more similarly to children with ADHD, and (c) children with ADHD have disproportionate difficulties retaining information across a delay, which occurs even when not faced with external distractors that produce interference effects and/or reallocate attention to prevent rehearsal of to-be-recalled stimuli (Bolden, Rapport, Raiker, Sarver, & Kofler, 2012; Lemaire & Portrat, 2018).…”

Consistent Failure to Produce a Cognitive Load Effect in Visual Working Memory Using a Standard Dual-Task Procedure

“…Thus, the cognitive load of the secondary task has an inverse relationship to the total number of items that can be maintained in working memory. There are several alternative models of cognitive load effects with somewhat different assumptions, but all of them predict a strong, inverse relationship between cognitive load and the total number of items remembered in dual-task situations (Lemaire & Portrat, 2018;Oberauer & Lewandowsky, 2011;Oberauer, Lewandowsky, Farrell, Jarrold, & Greaves, 2012;Portrat & Lemaire, 2015). Accordingly, the cognitive load effect has been proposed to be a Priority-A benchmark any model of working memory should be able to explain (Oberauer et al, 2018), in part because the effect appears to generalize across different experimental procedures and materials.…”

Current controversies in the cognitive science of short-term memory

“…It is easy to feel despondent about the state of short-term memory research: how can we have so much evidence yet so few firm conclusions? In light of this, there are grounds for thinking that a move away from a narrow systems-based approach to short-term memory may offer at the very least some new avenues of investigation, whether in the form of active inference frameworks [65], computational approaches [66], or simply better theory-neutral benchmarks for assessing competing models [67]. Likewise, while neuroscientific data has long played an important role in informing and constraining theoretical debates about short-term memory, one might hope that by identifying or modelling specific memory mechanisms -such as the oscillatory properties of neurons encoding working memory information [68] -new light may be shed on longstanding debates, especially in light of ongoing progress in neuroimaging techniques.…”