Mechanism of length perception by dynamic touch-proposal of identification-perception model considering proprioception

Studies on dynamic touch have indicated that humans can estimate the length of a rod held in one hand simply by static holding or wielding it, without any visual information. Traditionally, these types of studies have held that proprioception is important for perceiving the length, but this has not been demonstrated experimentally. In order to present appropriate information by haptic and kinesthetic information devices, it is important to understand human basic haptic and kinesthetic characteristic as a mechanical system. In the present paper, we proposed identification-perception model based on proprioception, which was constructed by adopting system identification method considering human as one mechanical system. The originality of the model is that human cannot perceive rod´s length, they only identify physical invariants. Moreover, in the model, humans select higher order information, when several physical invariants are available. The proposed model was verified by static holding experiment and dynamic touch experiment. The experimental results gave support to the proposed model. Moreover, human should perceived rod´s length by using vibratory information with not only proprioceptive information but also cutaneous information.