Influence of an interpolated non-related motor task on short- and long-term memory learning and retention of a gross motor skill.

A control group of young men (N = 28) continuously practiced climbing a free-standing ladder for 20 1-min. "trials" separated by 1-min. rests; after a 1-wk. layoff they practiced 5 additional trials. The learning trend, of the exponential form, y = c - a1e -kx1 - a2e -kx2 was not affected by the layoff. Another group (N = 28) performed the skill in the same manner, except that prior to the layoff the 1-min. Rests were replaced with practice on the pursuit rotor task. This caused a cumulative learning deficit and forgetting during the layoff. Progressive improvement in 5 post-layoff trials (without the rotor) established relearning and overcame the deficit. These effects were statistically significant. They were thought to be caused by the rotor practice interfering with just-learned ladder skill consolidation, so that the gain in skill was not processed into long-term memory.