The skilled performance positivity after learning a skilled task.

The effect of an intensive training period and that of a time-distributed training on skilled performance positivity (SPP) have been studied. SPP is a potential associated with knowledge and evaluation of the results of a goal-directed bimanual self-paced task requiring particular ability. Nine subjects with average intelligence but with some difficulties in the motor-perceptive sphere were studied. The task consisted of initiating the sweep of an oscilloscope with a self-paced movement and terminating it within 50 msec +/- 10 msec. The subjects had to repeat this task several times at various time intervals. The electrical activity was recorded from Fpz, Fz, Cz, Pz, P4, P3 and the right/left precentral areas. For each performance, performance time, performance shift taken as the accuracy index, as well as the percentage of target performances were evaluated. Motor performances improved with both distributed and intensive practice. Only distributed practice had a significant effect on SPP latency and amplitude. SPP latency decreased in all brain areas, whereas amplitude increased in the prefrontal, frontal and left precentral areas. These results seem to suggest that the performance evaluation processes take place more quickly and efficiently through distributed practice.