Sensory Integration of Apparent Motion Speed and Vibration Magnitude

Abstract

Abstract-Tactile apparent motion can display directional information in an intuitive way. It can for example be used to give directions to visually impaired individuals, or for waypoint navigation while cycling on busy streets, when vision or audition should not be loaded further. However, although humans can detect very short tactile patterns, discriminating between similar motion speeds has been shown to be difficult. Here we develop and investigate a method where the speed of tactile apparent motion around the user's wrist is coupled with vibration magnitude. This redundant coupling is used to produce tactile patterns from slow&weak to fast&strong. We compared the just noticeable difference (JND) of the coupled and the individual variables. The results show that the perception of the coupled variable can be characterised by JND smaller than JNDs of the individual variables. This allowed us to create short tactile pattens (tactons) for display of direction and speed, which can be distinguished significantly better than tactons based on motion alone. Additionally, most subjects were also able to identify the coupled-variable tactons better than the magnitude-based tactons.

Tactile Edges and Motion via Patterned Microstimulation of the Human Cortex

“…To explore this feature, we varied the temporal activation of two adjacent PFs, and asked the participants to identify which of two mICMS patterns they perceived to be faster ( Figure 4D and Movie S6 ). Both participants were able to discriminate motion speed with a Weber Fraction of 0.56 ± 0.09 for both C1 and C2, which falls in the same range as natural touch 37 . In other words, the speed sensitivity of artificial stimuli is similar to that of tactile stimuli applied directly on the skin.…”

“…Speed discrimination performance for both C1 and C2 are reported. All the Weber fractions (WFs) are displayed in relationship with the natural range of our skin perception 37 (green zone).…”

A Suite of Robotic Solutions for Nuclear Waste Decommissioning

“…Providing tactile feedback to a human operator is another key factor in achieving safe and successful task completion in remote robotic manipulation. Traditional haptic interfaces can generate force or vibrotactile feedback to characterise the haptic properties of the remote environment; therefore, we have explored the use of simple vibration motors as a very affordable and portable solution [77][78][79][80][81]. However, very few of these solutions can simultaneously render force, texture, and shape.…”