Manipulating Drivers' Mental Workload: Neuroergonomic Evaluation of the Speed Regulation N-Back Task Using NASA-TLX and Auditory P3a

TL;DR

This study empirically evaluates a modified speed regulation n-back task as a tool to manipulate drivers' mental workload in simulators, using NASA-TLX and P3a ERP measures to validate its effectiveness.

Contribution

It introduces and validates a non-intrusive, reproducible method to manipulate mental workload in driving studies using a speed regulation n-back task.

Findings

Higher NASA-TLX scores in 2-back condition indicate increased workload.

Reduced P3a amplitude during 2-back suggests higher mental workload and resource allocation.

The method is effective and reproducible for manipulating driver mental workload.

Abstract

Manipulating MW in driving simulator studies without the need to introduce a non-driving-related task remains challenging. This study aims to empirically evaluate the modified speed regulation n-back task, a tool to manipulate drivers' MW. Our experiment involved 23 participants who experienced a 0-back and 2-back driving condition, with task-irrelevant novel environmental sounds used to elicit P3a event-related potentials. Results indicate that the 2-back condition was perceived as more demanding, evidenced by higher NASA-TLX scores (overall score, mental and temporal demand, effort, frustration). The mean P3a amplitude was diminished during the 2-back condition compared to the 0-back condition, suggesting that drivers experienced higher MW and had fewer resources available to process the novel environmental sounds. This study provides empirical evidence indicating that the speed regulation n-back task could be a valid, effective, and reproducible method to manipulate MW in driving research.