Blocked and alternating variable practice and unintended spatial variations in continuous aiming movements.

The main goal of the study was to test a prediction of schema theory: a wider range of variable practice would result in better transfer performance compared to a narrower range of variable practice in less-studied, continuous aiming movements. Constant and variable amplitude continuous aiming movements were investigated in the preferred hand of participants of college age (N = 32; 8 men, 24 women). Participants made continuous rapid reversal movements with a lever in the horizontal plane. Groups attempted to reach a short (20 degrees) target and a long target (either 45 degrees or 70 degrees) in separate constant-practice conditions, but alternated between the two targets in a variable practice condition. On the transfer test, participants alternated between unpracticed 10 degrees and 80 degrees targets. Four blocks of practice trials were provided in each condition, with 20 movements made in each. Movements were more accurate and consistent during constant practice compared to variable practice, with the 20 degrees-70 degrees group having greater spatial errors compared to the 20 degrees-45 degrees group. Both groups performed equally well on the novel transfer test suggesting that adequate practice variability had been provided during acquisition.