Contextual interference and motor skill learning in Alzheimer's disease

This study examined the acquisition, retention, and transfer of a gross mot or skill, namely, tossing, in 84 moderate-to-severely demented patients wit h Alzheimer's disease (AD) and 72 healthy elderly controls. To identify opt imal learning strategies, participants received 10 weeks of training under 1 of 5 practice conditions: constant, variable-parameter, variable-program, variable-combined, or no training. Constant practice was the only training condition that significantly enhanced learning and near transfer in AD pat ients. In comparison, all 4 types of training facilitated acquisition and n ear transfer in the healthy controls, with variable-combined practice being the most beneficial. The superiority of the variable practice conditions i n the healthy controls supports both Schmidt's (1975) variability of practi ce hypothesis and contextual interference theory. The inability of AD patie nts to benefit from variable forms of practice suggests that these impaired individuals may have difficulty accessing and/or forming motor schemas.