Learning to throw: Contributions of contextual interference and individual differences to the acquisition of a complex motor skill

Abstract The acquisition of motor skills is influenced by several factors. Feedback, training schedule and individual differences between learners are three of them and were investigated in the present thesis. A special focus was on brain processes underlying feedback processing and motor preparation. These were investigated using event related potentials (ERPs). In a large study, we trained 120 participants to throw at virtual targets and tested them in a subsequent session for retention and transfer. ERPs were recorded in both sessions. Training schedule was manipulated with half of the participants practicing under high contextual interference (CI) (randomized training) and the other half under low CI (blocked training). In a follow-up online study, 80% of the participants completed a subset of the Raven advanced progressive matrices, testing their reasoning ability. We could show, that under high CI, participants’ reasoning ability was related to higher performance increase during training and higher subsequent performance in retention and transfer. Similar effects of reasoning ability on performance increase in late stages of low CI training indicate, that variability is a necessary prerequisite for beneficial effects of reasoning ability. We conclude, that CI affects the amount of variability of practice across the course of training and thereby modulates whetherThe acquisition of motor skills is influenced by several factors. Feedback, training schedule and individual differences between learners are three of them and were investigated in the present thesis. A special focus was on brain processes underlying feedback processing and motor preparation. These were investigated using event related potentials (ERPs). In a large study, we trained 120 participants to throw at virtual targets and tested them in a subsequent session for retention and transfer. ERPs were recorded in both sessions. Training schedule was manipulated with half of the participants practicing under high contextual interference (CI) (randomized training) and the other half under low CI (blocked training). In a follow-up online study, 80% of the participants completed a subset of the Raven advanced progressive matrices, testing their reasoning ability. We could show, that under high CI, participants’ reasoning ability was related to higher performance increase during training and higher subsequent performance in retention and transfer. Similar effects of reasoning ability on performance increase in late stages of low CI training indicate, that variability is a necessary prerequisite for beneficial effects of reasoning ability. We conclude, that CI affects the amount of variability of practice across the course of training and thereby modulates whether learning is rule-based or pattern-based (Study 1). This interpretation is fostered by findings of differential learning effects on ERPs in the preparatory phase. High CI shows a larger decline in attentionand control-related ERPs than low CI. Moreover, CNV amplitude, as a measure of motor preparatory activity, increases with learning only, when attention demands of training and retention are similar, as in low CI training. This points to two parallel mechanisms in motor learning, with a cognitive and a motor processor, mutually contributing to CNV amplitude (Study 2). In the framework of the “reinforcement learning theory of the error related negativity”, we showed, that positive performance feedback is processed gradually and that this processing is reflected in varying amplitudes of reward positivity (Study 3). Together these results provide new insights on motor learning.