Determining appropriate parameters to elicit linear and circular apparent motion using vibrotactile cues

This paper reports on two experiments we conducted to look at how to design effective linear and circular apparent-motion displays. Using a two-tactor array on the upper arm, the first study found that a time interval of greater than 400 ms before repeating the directional sequence is required for subjects to achieve 95 % proficiency of direction identification over a range of duration of stimulus (DOS) and stimulus onset asynchrony (SOA) values. The second study looked at the number of tactors necessary in a circular tactor array on the upper arm for people to correctly identify the direction of the rotation. We found that subjects could achieve a proficiency approaching 100 % across a large range of DOS and SOA values with four tactors, using a circuit-completion time of 400 ms or longer. These findings can be used by interface designers to realize information displays that either stand on their own, or work in combination with visual and/or audio displays.