Effect of Normal Force Intensity on Tactile Motion Speed Perception Based on Spatiotemporal Cue

Area of Science:

• Neuroscience
• Haptics
• Human Perception

Background:

• Tactile motion perception is crucial for everyday interactions.
• Previous research integrated multiple tactile cues, obscuring the role of normal force.
• Understanding normal force's isolated effect on tactile speed perception is limited.

Purpose of the Study:

• To investigate the effect of normal force on tactile speed perception using only the spatiotemporal cue.
• To isolate and quantify the influence of normal force intensity on perceived tactile speed.

Main Methods:

• Developed a novel pin-array display to independently control normal force.
• Conducted two psychophysical experiments to assess tactile speed perception.
• Varied normal force intensity while eliminating tangential forces and slip-induced vibrations.

Main Results:

• Doubling normal force intensity increased perceived tactile speed by 1.12-1.14 times.
• No significant difference in tactile speed discriminability was observed with varying normal force.

Conclusions:

• Normal force significantly enhances the perceived speed of tactile motion via spatiotemporal cues.
• Normal force intensity does not influence the ability to discriminate between different tactile speeds.
• Findings provide insights for designing haptic displays relying on normal force for spatiotemporal feedback.