to both of the tasks and their statistics. While this was not thought to characterize human learning (a supposed weakness of this approach), recent evidence suggests that human learning also exhibits this principle under the right conditions (Mirman & Spivey, 2001). In science Neuroscience techniques have recently been applied to investigating the effects of varied practice. Because these effects are typically only observed after a considerable delay, these studies have focused on the neural changes occurring during the consolidation period. For example, Kantak and colleagues (2010) used repetitive transcranial magnetic stimulation (rTMS) immediately after varied practice of a motor task and, in a separate group of participants, after traditional constant practice of the same task. When the rTMS was applied over the prefrontal cortex, performance 24 hours after training was much worse than immediately after training. In contrast, when the rTMS was applied over primary motor cortex, performance 24 hours after training improved similarly to a control group that received no rTMS. Thus, disruption of neural activation in the prefrontal cortex after varied practice appears to eliminate its benefits. In contrast, when a constant practice schedule was used, all groups performed worse 24 hours after training than immediately after training, and the group receiving rTMS over the primary motor cortex performed much worse than either the prefrontal or control groups. In sum, the findings suggest that varied and constant practice engage distinct sets of neural regions, the former involving the prefrontal cortex and the latter involving primary motor cortex. In education The practical benefits for varied practice in the educational domain may be largely untapped. Dempster and Corkill (1999) argued that the available evidence warranted focused investigations of the role of these underlying processes (cognitive inhibition and contextual interference) to the teaching-learning process. More recently, Rohrer and his colleagues studied the benefits of varied practice in mathematics curricula. Rohrer and Taylor (2007) noted that, contrary to the basic science supporting the varied practice approach, most mathematics textbooks had each set of practice sections made up almost entirely of problems corresponding to the immediately previous lesson; only in a small number of cases did they find the practice problems to be systematically shuffled so that each practice set includes a variety of problems drawn from many previous lessons. They concluded that varied practice was underused. Apfelbaum, Hazeltine and McMurray (2013) found consistent benefits of varied practice for children learning phonics regularities