Perceptual Effects of Cutaneous Rabbit Illusions in the Palm Using Ultrasound Haptics

Ultrasound haptic devices allow users to experience haptic sensations in a non-contact environment. To enhance perceptual precision, it is crucial to account for the effects of haptic illusions during the rendering process. This study investigates the perceptual mechanisms behind the cutaneous rabbit illusion on the palm using ultrasound haptics. We introduce a comprehensive mathematical model to quantify how the illusion distorts the perceived spatial location of stimuli, focusing on the spatiotemporal decay of perceived intensity and the accumulation effect over the duration. Our findings reveal that the key parameter determining the intensity of the cutaneous rabbit illusion is the interval between the end times of the two stimuli. We derive a simple formula relating the perceived location and the actual stimulus location, which provides practical insights for improving ultrasound haptic rendering techniques.