Tapping Regularity as a Measure of Perceptual Motor Load

Abstract

Numerous methods have been devised to measure perceptual load. Unfortunately the concept itself is ill-defined, which makes different approaches practically incomparable.

The central problem is the ordering of tasks of different types. Most methods compare tasks that differ only in one variable, such as speed or input/output uncertainty. There are however methods which can be applied to a wider range of tasks.

One such approach observes the timing of successive actions: load will cause ‘ traffic control’ problems in the central nervous system, so that actions will be executed in an irregular fashion.

The use of irregularity as a measure of perceptual load depends on the availability of a ‘ functional ’ descriptive system of behaviour, as opposed to current ‘ phenomenal ’ systems like those of time and motion study. A convenient substitute ia that of measuring the irregularity of a subsidiary performance. Key tapping was found to satisfy certain methodological requirements. Some experiments evaluating this method are discussed.