Motor learning characterized by changing Lévy distributions.
The probability distributions for changes in transverse plane fingertip speed are Lévy distributed in human pole balancing. Six subjects learned to balance a pole on their index finger over three sessions while sitting and standing. The Lévy or decay exponent decreased as a function of learning, showing reduced decay in the probability for large speed steps and was significantly smaller in the sitting condition. However, the probability distribution for changes in fingertip speed was truncated so that the probability for large steps was reduced in this condition. These results show a learning-induced tolerance for large speed step sizes and demonstrate that motor learning in continuous tasks may be characterized by changing distributions that reflect sensorimotor skill acquisition.
Cluff
Tyler
T
Sensorimotor Neuroscience Laboratory, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada. clufft@mcmaster.ca
Balasubramaniam
Ramesh
R
D000328:Adult; D000465:Algorithms; D005246:Feedback; D005260:Female; D005385:Fingers; D006801:Humans; D007858:Learning; D008297:Male; D015233:Models, Statistical; D009043:Motor Activity; D009048:Motor Skills; D009415:Nerve Net; D004856:Postural Balance; D011597:Psychomotor Performance; D013269:Stochastic Processes