A Cautionary Note on Evidence-Accumulation Models of Response Inhibition in the Stop-Signal Paradigm

Dora Matzke,Gordon D Logan,Andrew Heathcote

doi:10.1007/s42113-020-00075-x

Abstract

The stop-signal paradigm is a popular procedure to investigate response inhibition—the ability to stop ongoing responses. It consists of a choice response time (RT) task that is occasionally interrupted by a stop stimulus signaling participants to withhold their response. Performance in the stop-signal paradigm is often formalized as race between a set of go runners triggered by the choice stimulus and a stop runner triggered by the stop signal. We investigated whether evidence-accumulation processes, which have been widely used in choice RT analysis, can serve as the runners in the stop-signal race model and support the estimation of psychologically meaningful parameters. We examined two types of the evidence-accumulation architectures: the racing Wald model (Logan et al. 2014) and a novel proposal based on the lognormal race (Heathcote and Love 2012). Using a series of simulation studies and fits to empirical data, we found that these models are not measurement models in the sense that the data-generating parameters cannot be recovered in realistic experimental designs.

Highlights

The stop-signal paradigm is a popular procedure to investigate response inhibition—the ability to stop ongoing responses
We report the results of a series of parameter-recovery studies aimed at investigating the measurement properties of the SSLNR and the stop-signal racing Wald model (SS-RW) as a function of the number of stopsignal trials
In the Supplemental Materials, we show that poor parameter recovery is not unique to the particular setup used in our simulations and is not necessarily improved by imposing highly informative prior distributions (Figures S15–S17)

Summary

Introduction

The stop-signal paradigm is a popular procedure to investigate response inhibition—the ability to stop ongoing responses It consists of a choice response time (RT) task that is occasionally interrupted by a stop stimulus signaling participants to withhold their response. The stop-signal race model plays a central role in response inhibition research because it enables the non-parametric estimation of the unobservable latency of the stop response, known as the stop-signal reaction time (SSRT; Colonius 1990; de Jong et al 1990; Logan and Cowan 1984; for an overview, see Matzke et al 2018). Reliable non-parametric estimates of SSRT can be obtained with as few as 50 stopsignal trials per participant (Verbruggen et al 2019)

Objectives

Findings

Discussion

Conclusion