New research has established the parameters needed for inducing phantom sensations, enhancing technologies like virtual reality and devices for the hearing impaired.
Individuals can experience the sense of touch without actual tactile stimulation. This phenomenon, known as “phantom sensation,” occurs when the nervous system perceives a tactile illusion that does not correspond to any real physical touch, effectively creating a sensation that does not exist.
Researchers from the “Electronics for Instrumentation and Systems” group at UMA have recently made significant advancements in understanding this phenomenon. For the first time, they have identified the minimum distance a vibrating point must travel for a person to perceive this moving phantom sensation.
Mechanism of Phantom Sensations
Professor Andrés Trujillo from the Department of Electronics, a co-author of the study, describes how the illusion of motion is created using two vibrating devices, known as vibrotactile actuators, placed at different locations on the skin. “With proper stimulation, an individual, instead of perceiving two isolated vibrations, can experience the feeling that there is a vibrating point moving between these two devices, although this point does not really exist, it is illusory,” he states.
According to Trujillo, the research conducted at UMA has allowed them to refine the configuration parameters previously used to induce phantom sensations. “We have developed an instruction manual to know the operating limits of this tactile illusion,” he says.
The researchers found that individuals can perceive the phantom motion of a vibrating point when the traveled distance is at least 20 percent of the gap between the actuators.
Potential Applications
One of the main applications of these tactile illusions is in virtual and augmented reality. The ability to create moving sensations with just a few actuators offers a major advantage, potentially leading to the development of cost-effective, lighter, and higher-resolution devices. “The conventional application would be to place a series of actuators, not just two, and systematically switch them on and off to create the feeling of movement,” says Trujillo.
Additionally, this technology could enhance haptic vests, video games, touch screens for the blind, and even concerts, providing users with enhanced realism and new sensations.
This study, published in Displays, is the result of the doctoral thesis of researcher Paul Byron Remache-Vinueza, directed by the Professor of the School of Industrial Engineering Fernando Vidal and Andrés Trujillo. Their research aims to transmit musical sensations through the skin to assist people with hearing impairments.
Reference: “Phantom sensation: Threshold and quality indicators of a tactile illusion of motion” by Byron Remache-Vinueza, Andrés Trujillo-León and Fernando Vidal-Verdú, 13 March 2024, Displays.
DOI: 10.1016/j.displa.2024.102676
