title: A developmental study of the relationship between geometry and kinematics in drawing movements.
abstract: Trajectory and kinematics of drawing movements are mutually constrained by functional relationships that reduce the degrees of freedom of the hand-arm system. Previous investigations of these relationships are extended here by considering their development in children between 5 and 12 years of age. Performances in a simple motor task--the continuous tracing of elliptic trajectories--demonstrate that both the phenomenon of isochrony (increase of the average movement velocity with the linear extent of the trajectory) and the so-called two-thirds power law (relation between tangential velocity and curvature) are qualitatively present already at the age of 5. The quantitative aspects of these regularities evolve with age, however, and steady-state adult performance is not attained even by the oldest children. The power-law formalism developed in previous reports is generalized to encompass these developmental aspects of the control of movement.
authors.affiliation: Faculty of Psychology and Educational Sciences, University of Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Viviani
authors.forename: R
authors.initials: R
authors.lastname: Schneider
mesh_terms: D000328:Adult; D001288:Attention; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003210:Concept Formation; D005260:Female; D006801:Humans; D007699:Kinesthesis; D008297:Male; D009048:Motor Skills; D009949:Orientation; D011601:Psychophysics