Author:

Keywords:

contextual interference, fMRI, aging, motor learning

Abstract:

In the past decades, a lot of research has been dedicated to the optimization of training paradigms in motor skill learning. The key question is how to compose a training schedule to guide the learner towards the best possible outcome. Although blocked practice (i.e. constant repetition of a task variant before moving on to the next) is conventional in different settings, it does not seem to be the best approach. As such, the variance in presentation order of different task variants, i.e. contextual interference (CI), is shown to be paramount for learning outcomes. Research has provided compelling evidence regarding the CI effect, i.e. the beneficial effect of a random compared to a blocked practice schedule on motor learning, despite detrimental effects on the acquisition phase. Although the CI effect is a robust phenomenon in simple task learning, its generalization to rather complex tasks is still debated. Furthermore, little is known about the neural correlates of the CI effect, which hampers knowledge about the underlying mechanism that gives rise to the CI effect. On these grounds, this study aimed to investigate the CI effect in a complex bimanual task on a behavioral and neuroimaging level by using functional magnetic resonance imaging (fMRI). To this end, 32 younger adults were randomly assigned to either a random or a blocked practice group. Each participant completed a baseline assessment followed by 3 days of training. Finally, a retention test was carried out 6 days afterwards. Whereas behavioral results were explored for all participants, preliminary neuroimaging data are presented for a subsample of 10 subjects. Behavioral results support the advantage of random practice on retention despite poorer performance during the acquisition phase compared to blocked practice. Investigating the neural correlates during the acquisition phase, the blocked practice group mainly relied on brain areas involved in basic bimanual coordination (sensorimotor areas, cerebellum and subcortical structures), whereas higher-order areas, such as the premotor cortex, were activated in random practice. During retention, the random group, demonstrated an additional activation of higher-order structures needed to retrieve memory and optimize the integration of sensory information (e.g. precuneus). These findings suggest that the benefit of random practice might arise from a more profound cognitive engagement, which is of great importance in the optimization of training schedules.