Assessing the benefits of multimodal feedback on dual-task performance under demanding conditions

The last few years have seen the release of an increasing number of new IT-related devices into the marketplace that have started to utilize tactile feedback. These include those devices incorporating a touch screen that make multimodal feedback incorporating the delivery of two or more sensory modalities possible. The commonly-held view is that the use of such multimodal (or multisensory) feedback, involving the presentation of information to two or more sensory modalities ought, if anything, to improve the usability, performance, and satisfaction of the interface. In particular, an especially beneficial effect of multimodal feedback might be expected in those situations that are highly perceptually and/or cognitively demanding, such as driving a car or monitoring a complex system. In the present study, we examined the potential beneficial effect of the multimodal feedback provided by a touch screen on participants’ performance in a perceptually demanding dual-task situation. We compared unimodal (visual) feedback with various kinds of multimodal (bimodal and trimodal) feedback. In addition, we also investigated the consequences of varying the intensity and number of multimodal feedback signals that were presented on driver performance (Experiment 2). Overall, the results of the two experiments reported here show that the presentation of multimodal feedback results in enhanced performance and more pronounced benefits as the intensity of the feedback signals presented to the different modalities is increased.