Interpolated activities during the knowledge-of-results delay and post^knowledge-of-results interval: Effects on performance and learning.

In the present experiments, the effect of involvement in attention-demanding recognition activities (secondary task) during the KR delay interval on learning/retention of a timing movement (primary task) was investigated. Findings of Experiment 1 and 2 revealed that the interpolated task interfered with the primary task, resulting in inferior retention performance. In a third experiment, the temporal location of the secondary task was manipulated through its interpolation in the KR delay and the post-KR interval across different conditions. In contradiction to earlier predictions, the secondary task tended to generate less interference when administered in the post-KR interval in comparison with the KR delay interval. Current findings raise doubts about the hypothesized minor role of the KR delay interval for learning/retention and indirectly point to important information-processing activities that occur during this interval (Swinnen, Schmidt, Niebolson, & Shapiro, 1990).