Design and Validation of Vibrotactile Communications for Dynamic Environments

Vibrotactile displays are advantageous in task environments where visual and auditory channels are saturated or environmentally undesirable. These immediate, private stimuli are tied to our cognitive embodiment and well-suited for providing physical directions and speeded signals under cognitive workload and reducing competition for shared mental resources. However, these strengths depend on the development of robust communication systems. Highly dynamic domain environments necessitate error management, which pushes cognition into increasingly slow, reflective modes where touch is less beneficial. The design of vibrotactile displays should either focus development on more limited domains or face the sizeable challenge of developing an adaptable vibrotactile language to handle unanticipated changes. This work advances the science of vibrotactile display development by demonstrating that superior resolution can be achieved through temporal overlap and the saltation illusion and, second, by establishing a method for the development of ordinal signals via subjective intensity ratings. It also demonstrates that more embodied interfaces, (i.e.: touch and gesture), provide shorter, more direct communication for speeded physical tasks by shortening the “Gulf of Action”. Finally, it provides evidence that vibrotactile interfaces are useful as alerting systems under cognitive load, particularly for general aviation contexts, but also other highly demanding environments where graded warnings may improve situation awareness during demanding primary tasks