Creating an Illusion of Movement between the Hands Using Mid-Air Touch

Area of Science:

• Neuroscience
• Psychology
• Human-Computer Interaction

Background:

• The tactile illusion of apparent motion can occur on contiguous body parts.
• This illusion has recently been extended to non-contiguous body parts, including between hands, with or without physical connection.

Purpose of the Study:

• To investigate the reproducibility of the intermanual tactile illusion of movement between two free hands using mid-air tactile stimulation.
• To explore optimal parameters for generating continuous and smooth tactile motion.
• To compare static versus dynamic focal point stimulation techniques for eliciting the illusion.

Main Methods:

• Utilized two arrays of ultrasound speakers for mid-air tactile stimulation.
• Employed two stimulation techniques: static focal point and dynamic focal point.
• Conducted experiments to assess the occurrence and characteristics of the intermanual tactile illusion.

Main Results:

• The intermanual tactile illusion of movement was successfully reproduced between two free hands using mid-air ultrasound stimulation.
• Optimal parameters for generating continuous and smooth perceived motion were identified for both static and dynamic focal point techniques.
• Two distinct perceptive models were defined based on the experimental findings for each stimulation technique.

Conclusions:

• Mid-air tactile stimulation is a viable method for inducing the intermanual tactile illusion.
• Both static and dynamic focal point techniques can elicit the illusion, with specific parameters influencing perceived motion quality.
• The study provides insights into the mechanisms underlying tactile motion perception between non-contiguous body parts.