ABSTRACT
We examined the temporal invariance hypothesis in handwriting, using dynamic programming (DP) matching algorithm. The DP matching algorithm was originally developed for the speech recognition to eliminate fluctuations of time axis caused by different speech rates. This algorithm can determine the optimal point-to-point correspondences (warping function) between the standard velocity pattern and different patterns. We found that this algorithm worked well for various velocity patterns, even when their total writing time was different from the standard pattern. Only 30 to 50 percent of handwriting movements showed temporal invariance. The writing movements which didn't show temporal invariance consisted of several sub-motor units. The borders between the units were not limited near the end of each letter. The results suggest that handwriting of a word does not show the temporal invariance and that it is executed by some discrete sub-motor units.
Subject(s)
Algorithms , Handwriting , Software , Adult , Feedback , Humans , Movement , Pattern Recognition, Automated , Psychomotor Performance , TimeABSTRACT
The effects of delay of visual feedback on two kinds of sensorimotor tasks were investigated. On the reciprocal tapping task, accuracy of performance decreased for 200, 500, and 767 msec. delay. The number of errors for the 1000-msec. delay is smaller than those for the other three conditions of delay. On the hand-writing task of both Kanji letters and English words, performance showed a large decrement with increasing delay. The most frequent kinds of error were the type of insertion of line elements or letter duplication. It was interesting that the size of written letters increased with lengthening delays of visual feedback.
