An Estimation and Comparison of Human Abilities to Communicate Information Through Pursuit Tracking vs. Pointing on a Single Axis

Abstract

This paper describes a human subject study that compared the limits at which humans could communicate information through pursuit tracking gestures versus pointing (i.e. tapping) gestures. These limits were measured by estimating the channel capacity of the human motor-control system for pursuit tracking versus pointing along a single axis. A human-computer interface was built for this purpose, consisting of a touch strip sensor co-located with a visual display. Bandwidth-limited Gaussian noise signals were used to create targets for subjects to follow, enabling estimation of the channel capacity at bandwidth limits ranging from 0.12 Hz to 12 Hz. Results indicate that for lower frequencies of movement (from 0.12 Hz to 1 Hz or 1.5 Hz), pointing gestures with such a sensor may tend to convey more information, whereas at higher frequencies (from 2.3 Hz or 2.9 Hz to as high as 12 Hz), pursuit tracking gestures will afford higher channel capacities. In this work, the direct comparison between pursuit tracking and pointing was made possible through application of the Nyquist sampling theorem. This study forms a methodological basis for comparing a wide range of continuous sensors and human capacities for controlling them. In this manner, the authors are aiming to eventually create knowledge useful for theorizing about and creating new kinds of computer-based musical instruments using diverse, ergonomic arrangements of continuous sensors.