On the Origin of Asymmetric Bell-Shaped Velocity Profiles in Rapid-Aimed Movements

Abstract

This paper proposes a stochastical model for the origin and the invariance of the bell-shaped velocity profiles, as frequently reported in studies dealing with rapid aimed movements. The model describes these movements as originating from the sequential action of a set of velocity generators working in cascade. Applying the central limit theorem to describe the converging behavior of such a system, it is shown that velocity profiles can be described by log-normal curves. Results of an analysis by synthesis experiment are reported and some consequences of this approach to the study of human movement are discussed. A unified view of the speed-accuracy trade-offs is proposed as a direct consequence of this approach.