Spacetime trajectories as overlapping rhythms

The navigation of two-dimensional spaces by rhythmic patterns on two buttons is investigated. It is shown how direction and speed of a moving object can be controlled with discrete commands consisting of duplets or triplets of taps, whose rate is proportional to one of two orthogonal velocity components. The imparted commands generate polyrhythms and polytempi that can be used to monitor the object movement by perceptual streaming. Tacking back and forth must be used to make progress along certain directions, similarly to sailing a boat upwind. The proposed rhythmic velocity-control technique is tested with a target-following task. Users effectively learn the tapping control actions, and they can keep a relatively small distance from a moving target. They can potentially rely on overlapping auditory rhythmic streams to compensate for temporary deprivation of visual position of the controlled object. The interface is minimal and symmetric, and can be adapted to different sensing and display devices, exploiting the symmetry of the human body and the ability to follow two concurrent rhythmic streams.