Fractal correlation of initial trajectory dynamics vanishes at the movement end point in human rapid goal-directed movements

Neurosci Lett. 2001 May 25;304(3):173-6. doi: 10.1016/s0304-3940(01)01779-7.

Abstract

Many researchers have investigated the variability of discrete goal-directed movements. However, a possible time-dependent property for them has been ignored. We investigated the time-dependent property of the kinematic variability in human rapid goal-directed movements by using fractal analysis. The variability of the peak acceleration had fractal time correlation characterized by a non-negligible frequency-spectral exponent (beta=0.3). This beta value was reduced at the peak velocity (beta=0.2) and nearly reached zero at the peak movement amplitude, indicating that the variability became white noise with no time correlation. A similar result was observed in the progress of the positional trajectory. The functional significance of this phenomenon for the goal-directed task demand is discussed.

MeSH terms

  • Acceleration
  • Adult
  • Biomechanical Phenomena
  • Female
  • Fractals*
  • Humans
  • Male
  • Psychomotor Performance / physiology*