ABSTRACT. The authors investigated the time scales of the learning of a mirror-tracing task to reexamine G. S. Snoddy's (1926) original claim and the received theoretical view (A. Newell & E S. Rosenbloom, 1981) that motor learning follows a power law. Adult participants (N = 16) learned the tracing task in either a normal or a reversed visual-image condition over 5 consecutive days of practice and then performed I day of practice 1 week later and again 1 month later. The reversed-image group's performance was poorer than that of the normal-image group throughout the practice. An exponential was the best fitting function on individual data, but the power-law function was the ...
<.01, were significant. Overall, the function fits were higher for the exponential function than for the power-law function and were generally lower as we added more days of practice into the analysis. As Tukey pairwise comparisons of the main effect for practice period showed, the fits of the 1st day were significantly different from those of all longer practice durations. There was no difference between the two vision conditions for the function fits, and we found no interaction effects, ps><.0001. Although the effect of visual condition was not statistically significant, F(1, 12) = 1.46, p>