Response of SAI Afferents May Play a Role in the Perception of Velvet Hand Illusion

Abstract

Problem statement:We revealed the reason behind a haptic illusion called the Velvet Hand Illusion (VHI) by FEM analysis. In VHI, a person rubs his/her hands together on both sides of wires strung through a frame and produces the sensation of rubbing a very smooth and soft surface like velvet. We focus on VHI to determine the specifications of an actuator for a tactile display enhanced by VHI. Approach: A simulated fingertip was modeled under the same contact condition that an actual finger was believed to undergo when under VHI. We collected the simulated responses of a number of SAI afferents, which were responsible for detecting the edges, to relate them to the mechanism of the illusion. Results: Even with a simple model that treats only one finger, we noticed a considerable difference between the responses of a number of SAI receptors compared with that of a fingertip touching wires without the effect of the opposing finger. The SAI responses for the VHI case are less (some receptors' response is up to 50% less) than those for a finger touching the wires, which corresponds to a decrease of the perception of the wires. Conclusion/Recommendations: SAI might play a role in the mechanism of the VHI illusion. This study could benefit the development of a haptic display that utilizes the illusion and makes a person experience the same feeling using the proposed display.

A 3D FE dynamic model of human fingertip based on MRI data

“…They found that the strain energy is concentrated at the tactile receptor locations. A 2D FE fingertip model was also proposed by Chami et al to reveal the reason behind a haptic illusion called Velvet Hand Illusion (VHI) [10]. In addition, a 2D skin-receptor model combining an FE model of skin mechanics, a sigmoidal function of transduction, and a neural dynamics model was presented by Gerling et al to predict SA-I spike times in response to sustained indentation at the skin's surface [11].…”

“…Wu No. geometry geometry Viscosity behaviors [2] poor poor no no [3] poor fair no no 2D [9], [10] fair good no no [7], [8] poor fair yes yes [11] good good no yes [1] good fair no no 3D [12] fair fair no no [13] good fair no no into consideration to study the nonlinear and time-dependent force responses of fingertips during dynamic contact [6], [7], [8]. A 2D FE model of fingertip with detailed locations of various tactile receptors was proposed by Maeno et al to clarify the reason of the precise locations of these receptors [9].…”

Petri Nets and Ladder Logic for Fully-Automating and Programmable Logic Control of Semi-Automatic Machines and Systems

“…The research in (Youssef and Peng, 2010) proposed a method that could deal with fault-tolerant control system by using the decentralized control theory. The study in (Chami et al, 2010) proposed a way that revealed the reason behind a haptic illusion called the Velvet Hand Illusion (VHI) by fem analysis. The research in (Alfred, 2009) presented the optimizing feature construction process for dynamic aggregation of relational attributes.…”