Individual Differences in Two Motor Learning Tasks under Massed Practice

Abstract

50 boys, age 14 to 15 yr., were tested on a tracking task (pursuit rotor) and a large-muscle motor-learning task (stabilometer) to examine the effect of relatively massed practice upon individual differences and intra-individual variation. The practice schedule, which was identical for both tasks, called for 20 50-sec. practice trials with a 10-sec. intertrial rest period. A 5-min. rest was also interpolated every fourth trial. The greatest change in individual differences and intra-individual variation in both tasks occurred during the first 4 practice trials and in the 5-min. interpolated rest which immediately followed. Additional practice and interpolated rest over the remaining 15 practice trials had little additional effect upon either of the sources of variation. The changes in the sources of variation did not, with the exception of intra-individual variability in the stabilometer, appear to be proportional to changes in the mean.

Variability of manual dexterity performance in non-human primates (Macaca fascicularis

“…The CTs established at plateau were compared with those at the onset of the learning phase. The CT was assessed during the first four daily behavioral sessions (right panel in Figures 4A and B, for the horizontal and vertical slots, respectively), based on previous evidence that individual differences and intra-individual variations are greatest during the first four practice trials during motor learning (e.g., Carron & Leavitt, 1968;Marteniuk, 1974). The median CT values at onset of learning are clearly longer than those measured at plateau (Figure 4), reflecting a decrease in CT during the learning phase, corresponding to an enhancement of precision grip performance.…”