Practising complex dynamics with causal depth for better learning

The (re)learning of motor skills relevant to real environments and tools should emphasize the ability to anticipate complex dynamics. In this novel paradigm for unstable interactive sonification (UNISON) participants learned to entrain the dynamics of a chaotic system through their arm movements. Importantly, they only heard and their movement was fed back as input to one of the three dimensions of the system, meaning that this was an underactuated control problem. This form of practice led to learning and better generalization than in a control condition where the stimulus was a predictable sine wave. In a third condition, participants tried to synchronize with the chaotic stimulus but without the ability to control it. No learning and generalization was observed there. Next to confirming the role of unpredictable stimuli in optimizing skill acquisition, the paradigm could also serve to study the causal depth of anticipatory dynamics or predictive forward models.