Abstract. Alarm systems may take advantage of the tactile modality for allocation of attentional resources during the performance of demanding tasks in complex environments. The purpose of this study was to determine the effectiveness of a tactile warning during increasing levels of mental workload in a primary task. Three simulated flight task conditions varying in mental workload were presented while an “on-thigh” vibrotactile warning was randomly assessed. Generally, there was a decrement in overall warning response performance when task workload increased, but this tendency faded and plateaued as the level of task workload progressed. The observed pattern indicates that vibrotactile warning signals may offer a plausible mode for conveying information during increasing levels of primary task workload.
