Nerve Journey (aka Sensation Speed)
Exploratorium, San Francisco

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

Try having a friend tap your ankle and neck, simultaneously and rhythmically, about once per second. You'll be surprised to discover the sensations don’t feel simultaneous. Sensations from your ankle take 20-50 milliseconds longer to arrive in consciousness than from your closer-to-the-brain neck; a difference long enough to notice!

This inspired me to invent an electro-mechanical tapping machine, enabling visitors to experiment by timing sensations in their own bodies and reversing the effect. Visitors turn a knob to adjust the precise delay between taps (at their ankle and neck) until both feel simultaneous. Then, a computer display shows how long the actual delay they've settled upon is.

A very strange “aha” moment comes if one later reaches out and touches each tapper with a different hand. Since hand-to-brain nerve distances are equal for both arms, one feels the actual delay you just dialed-in, in stark contrast to how simultaneous it felt at your neck and shoulder!

In collaboration with Diane Whitmore.