Abstract
The theoretical explanations used to explain changes in performance during motor imagery and physical practice conditions are inconsistent when memory retrieval is and is not required. This study measured performance time and workload during acquisition, a retention test requiring memory retrieval, and a retention test not requiring memory retrieval using a key-pressing task. The participants were assigned to physical practice with or without instructions to learn or motor imagery with or without instructions to learn. A diagram of the keys was presented during the practice trials and the first retention test, but was not presented during the second test. The results revealed no effect for the learning instructions or performance changes during the practice phases. However, during both retention tests participants in the physical practice conditions performed significantly faster than those in the motor imagery conditions. Also, higher levels of workload were reported for the motor imagery conditions when the retention test required memory retrieval compared to the other phases. A discussion of the implications of workload on performance is presented with respect to varying practice conditions.