Solving the Correspondence Problem in Haptic/Multisensory Interface Design

Abstract

There has been a recent resurgence of interest in the use of haptic displays to augment human performance, and to provide an additional means of information transfer to interface operators whose visual and/or auditory modalities may be otherwise informationallyoverloaded (e.g., Gallace et al., 2007; Kaczmarek & Bach-y-Rita, 1995; Spence & Ho, 2008a; Yannier et al., 2008; Zlotnik, 1988). Over the last few years, researchers have investigated the use of tactile interfaces to provide assistance in a wide variety of settings including everything from vibrating belts to provide navigation support (Nagel et al., 2005) through to wrist watches that allow the user to tell the time by the pattern of vibration that they feel on their wrist (Toyssy et al., 2008). However, the more extravagant predictions made by early researchers regarding the potential uses of vibrotactile interfaces – that people would soon be monitoring the latest stock market figures via vibrating waist displays (see Geldard, 1974; Hennessy, 1966), and/or watching television using nothing more than a 20 by 20 array of vibrators on the back of their chairs (the so-called “tactile television”; Collins, 1970) – have, as yet, proved to be too far-fetched (even allowing for extensive practice to familiarize themselves with the devices concerned). The problem with the implementation of these predictions was that early researchers typically failed to account for the fundamental human limits on the processing of tactile information through artificial displays (e.g., see Gallace et al., 2007; Spence & Driver, 1997b, for reviews). Here, it is critical to note that humans are severely limited in their capacity to process information, and, if anything, the limits on the processing of tactile information seem to be far more restrictive than for visual or auditory modalities (see Spence & Gallace, 2007; Spence & Ho, 2008a). What is more, many vibrotactile interfaces were originally tested in the laboratory under conditions of unimodal sensory stimulation. In real-life environments, however, multiple senses are likely to be stimulated at the same time, and visual stimuli seem to have priority access to our attentional resources (Posner et al., 1976; Spence et al., 2001). Nevertheless, one area where there has been a lot of interest (and promise shown) in the last few years relates to the use of non-visual cues to facilitate people’s visual search performance. It is on this aspect of tactile and multisensory displays that this chapter will focus. 3