The Cerebellum Optimizes Perceptual Predictions about External Sensory Events

Perception and action are governed not only by sensory information but also by prior predictions about sensory events. These sensory predictions allow one to react more rapidly to predictable information in the environment [1] and to perceptually distinguish self-produced and externally produced sensations [2-6]. In order to be accurate, however, all sensory predictions need continuous recalibration to match the changing properties of the environment, the sensorimotor system, or both. Earlier studies showed that the cerebellum is crucial for the recalibration of sensory predictions capturing the sensory consequences of one's motor behavior [5, 7]. Here we asked whether the cerebellum, a structure intimately linked to plasticity within the motor domain [8-13], also accounts for the recalibration of sensory predictions about external sensory events within the perceptual domain in a nonmotor task. Cerebellar patients and healthy controls were equally able to predict the time of reappearance of a moving target that temporarily disappeared behind an occluder. However, patients were significantly impaired in recalibrating this spatiotemporal prediction to account for an experimentally added delay. This suggests that the cerebellum plays a domain-general role in fine tuning predictive models.