Spacing practice sessions across days earlier rather than later in training improves performance of a visuomotor skill.

Our goal was to determine whether the extent of off-line performance improvements on a visuomotor task depends on the amount of practice individuals experience prior to a 24-h between-session break. Subjects completed ten trials of a mirror-tracing task over two days. On Day 1, subjects experienced either one, three or seven trials. Twenty-four hours later subjects completed the remainder of the ten trials. Despite experiencing an equivalent number of total training trials, subjects experiencing the 24-h delay after one or three trials demonstrated off-line performance improvements, but those experiencing the delay after seven trials did not. Furthermore, the one- and three-trial groups reached a superior level of performance by the end of training relative to the seven-trial group.