NERVE JOURNEY (aka Sensation Speed)
Exploratorium, San Francisco

User Research: Formative
Cited in: Exhibit Designs for Girls’ Engagement

Try this: have a friend tap your ankle and neck simultaneously and rhythmically, about once per second. Surprisingly, the sensations won't feel simultaneous. Sensations from your ankle take 20-50 milliseconds longer to reach your consciousness than those from your neck, which is closer to your brain—a noticeable difference!

Inspired by this phenomenon, I created an electro-mechanical tapping machine. This device allows visitors to experiment with the timing of sensations in their own bodies and even reverse the effect. By turning a knob, they can adjust the delay between taps at the ankle and neck until both feel simultaneous. The computer display then shows the actual delay they've chosen.

An intriguing "aha" moment occurs when visitors touch each tapper with a different hand. Since the nerve distances to the brain are equal for both arms, they now feel the exact delay they previously adjusted, in stark contrast to the simultaneous sensation experienced at the neck and shoulder.