A cortico-cerebellar neural model for task control under incomplete instructions

Cerebellar-inspired motor control systems have been widely explored in robotics to achieve biologically plausible movement generation. However, most existing models rely heavily on high-dimensional instruction inputs during training, diverging from the input-efficient control observed in biological systems. In humans, effective motor learning often based on sparse or incomplete external feedback. It is possibly attributed to the interaction between multiple brain regions, especially the cortex and the cerebellum. In this study, we present a hierarchical cortico-cerebellar neural network model that investigates the neural mechanisms enabling motor control under incomplete or low-dimensional instructions. The evaluation results, measured by two complementary levels of evaluation metrics, demonstrate that the cortico-cerebellar model reduces dependency on external instruction without compromising trajectory smoothness. The model features a division of roles: the cortical network handles high-level action selection, while the cerebellar network executes motor commands by torque control, directly operating on a planar arm. Additionally, the cortex exhibits enhanced exploration indirectly driven by the stochastic characteristics of cerebellar torque control. Our results show that cortico-cerebellar coordination can facilitate robust and flexible control even with sparse instruction signals, suggesting a potential mechanism by which biological systems achieve efficient behavior under informational constraints. © 2026 Elsevier Ltd