1George Mason University, MS3F5, Fairfax, VA, USA
2Associate Professor, Director, Human Factors & Applied Cognition, Department of Psychology, George Mason University, Fairfax, V.A. 22030, U.S.A.
*Corresponding Author, Blewis10@gmu.edu
Online published on 27 November, 2018.
Perceived urgency scaling has shown promise in determining the urgency implied by various signals. However, traditional methods of scaling need to be validated in higher fidelity contexts with behavioral responses and under varying levels of cognitive load. The current study investigated behavioral and subjective responses to unimodal and bimodal alerts of high and low perceived urgency presented during simulated driving. Twenty-eight participants completed a simulated driving task and were required to respond to alerts varying by urgency level conveyed and modality (visual, auditory, tactile and their bimodal combinations) under high and low cognitive load. Participants were asked to press the brakes as hard as they perceived the signal to be urgent (Max Brake Force: FMAX). Bimodal alerts elicited faster responses than unimodal alerts, with visual alerts having a particularly poor average response time and more misses. Urgency ratings obtained through FMAX brake force were greater for auditory and bimodal alerts than for visual or tactile alerts. Implications for in-vehicle alert design are discussed.
multimodal alerts, DVI design, workload
