The Sound of One Eye Clapping: Tapping an Accurate Rhythm With Eye Movements

Abstract

As eye-controlled interfaces becomes increasingly viable, there is a need to better understand fundamental human-machine interaction capabilities between a human and a computer via an eye tracking device. Prior research has explored the maximum rate of input from a human to a computer, such as key-entry rates in eye-typing tasks, but there has been little or no work to determine capabilities and limitations with regards to delivering gaze-mediated commands at precise moments in time. This paper evaluates four different methods for converting real-time eye movement data into control signals—two fixation-based methods and two saccade-based methods. An experiment compares musicians’ ability to use each method to trigger the playing of sounds at precise times, and examines how quickly musicians are able to move their eyes to trigger correctly-timed, evenly-paced rhythms. The results indicate that fixation-based eye-control algorithms provide better timing control than saccade-based algorithms, and that people have a fundamental performance limitation for tapping out eye-controlled rhythms that lies somewhere between two and four beats per second.