Adaptation level and retroactive interference in motor short-term memory.

5 groups of 10 subjects were required to make and recall a linear self-generated arm-positioning movement. 4 of the groups made and recalled 4 interpolated self-generated positioning movements before the recall of the criterion was attempted. The lengths of the interpolated movements relative to the criterion varied from group to group. For one group all interpolated movements were longer, for another they were all shorter, and two groups produced alternating shorter and longer movements. Results indicated a significant difference in percentage algebraic error at recall of the criterion movement between the groups experiencing longer and experiencing shorter interpolated movements. The evidence is suggestive of two components in retroactive design studies, interference and adaptation level.