Control space of apparent haptic motion

In this paper we present three experiments to measure the control parameter space of apparent haptic motion using a variety of stimulation attributes and body sites. In Experiment 1 we measured the range of Stimulus Onset Asynchrony (SOA) that created the percept of continuous motion between two vibrating points on the dorsal forearm and on the back by varying the frequency, intensity and duration of stimulation. The SOA space for apparent motion varied with duration and body site but not with frequency and intensity of stimulation. In Experiment 2 we measured the SOA space for moving sensations when direction of motion and spacing between actuators were varied. On the forearm the SOA space was influenced by both the direction and spacing. However, on the back it was only affected by the direction of actuation. Finally, in Experiment 3 we measured the SOA space using four or more actuation points, creating two-dimensional apparent motion. The results of the present study are discussed in the context of designing haptic contents for movies, amusement rides and video games.