The generation of vibrotactile patterns on a linear array: Influences of body site, time, and presentation mode

Abstract

In order to provide information regarding orientation or direction, a convenient code employs vectors (lines) because they have both length and direction. Potential users of such information, encoded tactually, could include persons who are blind, as well as pilots, astronauts, and scuba divers, all of whom need to maintain spatial awareness in their respective unusual environments. In these situations, a tactile display can enhance environmental awareness. In this study, optimal parameters were explored for lines presented dynamically to the skin with vibrotactile arrays on three body sites, with veridical and saltatory presentation modes. Perceived length, straightness, spatial distribution, and smoothness were judged while the durations of the discrete taps making up the "drawn" dotted lines and the times between them were varied. The results indicate that the two modes produce equivalent sensations and that similar sets of timing parameters, within the ranges tested, result in "good" lines at each site.In situations in which vision and/or audition are absent or are available but limited by information overload, an efficient use of the available sensory modalities might be to employ the sense of touch for the accurate perception ofalerts, position, mobility, or navigation (see, e.g., Korteling & van Emmerik, 1998). With such a system, involving spatial orientation and attitude awareness, it might be necessary to present tactile patterns in different orientations, on different body sites, for extended periods oftime, and/or in the presence of distracting noise or competing stimuli from other sensory modalities. Thus, for best use, the tactile patterns employed should produce readily perceived sensations whose meanings are intuitive or at least, as Penders (1953) described, "meaningful within their situation" (p. 15). One such pattern could be a directional line, a vector. The purpose ofthe present experiments was to examine the parameters of linear vibrotactile patterns that would allow them to be readily appreciated. These include exploration of the body sites and presentation conditions for generating "good" vibrotactile lines, for even the simplest oflinear patterns can differ greatly in salience,

Virtual Training via Vibrotactile Arrays

“…The system used an array of tactors in a flight jacket to signal the true gravity vector (among other aspects) to the pilot's torso during complex flight maneuvers (Knapp, 2001). Similar research has been performed by van Erp (2000), and by Cholewiak with sensory-impaired (blind and deaf) individuals (Cholewiak & Collins, 2000;Cholewiak & Wollowitz, 1992). None of the known systems used tactor arrays to provide body pose collision awareness.…”

Cutaneous saltation within and across arms: A new measure of the saltation illusion in somatosensation

“…This cutaneous rabbit illusion is also present when two successive taps are delivered at one location, followed by a third at another location. The second tap is mislocalized, and the size of its illusory displacement toward the third tap depends on the interstimulus interval (ISI) separating these stimuli (Cholewiak & Collins, 2000;Geldard, 1975Geldard, , 1982Kilgard & Merzenich, 1995).…”

Vibrotactile Display of Flight Attitude with Combination of Multiple Coding Parameters

“…Spatial characteristics of a vibrotactile sensation is determined by the location of vibration stimulus on a vibrotactile display [30]. Of the four coding parameters shown in Table 2, the parameter of location is therefore mandatory to encode attitude information.…”