| Popis: |
Two influential paradigms, eyeblink conditioning and motor adaptation, have deepened our understanding of the theoretical and neural foundations of sensorimotor learning. Although both forms of error-based learning are dependent on the cerebellum, the two literatures typically operate within distinct theoretical frameworks. For eyeblink conditioning, the focus is on the formation of associations between an error signal and arbitrary stimuli. For adaptation, the error signal is used to modulate an internal model of a sensorimotor map for motor planning. Here we take a step towards an integrative account of these two forms of learning, examining the relevance of core concepts from associative learning for motor adaptation. Using a task that drives implicit adaptation of reaching movements, we paired movement-related feedback with neutral auditory or visual cues that served as conditioning stimuli (CSs). Trial-by trial changes in feedforward movement kinematics exhibited two key signatures of associative learning: Differential conditioning and compound conditioning. Moreover, after compound conditioning, a robust negative correlation was observed between responses to the two elemental CSs of the compound (i.e., overshadowing), consistent with the additivity principle posited by models of associative learning. Computational modeling demonstrated that these results could not be captured by conventional, context-insensitive algorithms used to describe motor adaptation. Associative learning effects in motor adaptation provide a proof-of-concept for linking cerebellar-dependent learning paradigms within a common theoretical framework. |
