Cognitive Control of Working Memory: A Model-Based Approach.

Russell J Boag,Anne C Trutti,Birte U Forstmann,Niek Stevenson,Zsuzsika Sjoerds,Roel Van Dooren

doi:10.3390/brainsci11060721

Abstract

Working memory (WM)-based decision making depends on a number of cognitive control processes that control the flow of information into and out of WM and ensure that only relevant information is held active in WM’s limited-capacity store. Although necessary for successful decision making, recent work has shown that these control processes impose performance costs on both the speed and accuracy of WM-based decisions. Using the reference-back task as a benchmark measure of WM control, we conducted evidence accumulation modeling to test several competing explanations for six benchmark empirical performance costs. Costs were driven by a combination of processes running outside of the decision stage (longer non-decision time) and inhibition of the prepotent response (lower drift rates) in trials requiring WM control. Individuals also set more cautious response thresholds when expecting to update WM with new information versus maintain existing information. We discuss the promise of this approach for understanding cognitive control in WM-based decision making.

Highlights

Posterior inference on model parameters indicated that updating, gating, and substitution costs were partly due to additional working memory (WM) control processes running outside of the decision stage and partly due to a reduction in the quality of information processing
Control operations involves inhibition of the prepotent response—by slowing the rate of evidence accumulation—to allow more time for active control processes to finish. This is in line with EEG work with the reference-back task suggesting that oscillatory signals related to conflict monitoring are involved in triggering WM control processes when the need to use them arises [23,24]
Event-triggered reactive inhibition of prepotent response drift rates has been reported in similar evidence accumulation modeling of event-based prospective memory, in which ongoing task drift rates were inhibited on trials containing an unexpected cue to perform a deferred action [31,32,33]

Summary

Introduction

A central problem faced by working memory (WM) is that of managing the tradeoff between stability—maintaining stable WM representations against interference—and flexibility—keeping WM up to date when goals and task demands change [1,2,3,4,5]. To solve this problem, WM relies on a number of cognitive control processes that control the flow of information into and out of WM and ensure that only relevant information occupies. The gate allows new information into WM (and old information out), which enables WM to remain up to date with information relevant to current goals and task demands [19,20]

Methods

Results

Discussion

Conclusion