Internal models of self-motion: neural computations by the vestibular cerebellum.

The vestibular cerebellum integrates multimodal sensory and motor information with vestibular input to compute internal models of self-motion. Adaptive plasticity in the floccular lobe underlies the vital computation that maintains vestibulo-ocular reflex calibration to ensure gaze stability. The anterior vermis plays a key role in two essential computations: (i) it transforms head-centered vestibular signals into the body-centered reference frame required for postural control, and (ii) it constructs a prediction of the sensory consequences of active self-motion. The nodulus and ventral uvula of the posterior vermis compute an internal representation of our spatial orientation and self-motion relative to gravity. The internal models underlying each of these computations are continually updated to account for constraints imposed by changes in the environment and/or neural mechanical dynamics. The vestibular cerebellum plays an essential role in maintaining our balance and ensuring perceptual stability during activities of daily living. Here I examine three key regions of the vestibular cerebellum: the floccular lobe, anterior vermis (lobules I–V), and nodulus and ventral uvula (lobules X–IX of the posterior vermis). These cerebellar regions encode vestibular information and combine it with extravestibular signals to create internal models of eye, head, and body movements, as well as their spatial orientation with respect to gravity. To account for changes in the external environment and/or biomechanics during self-motion, the neural mechanisms underlying these computations are continually updated to ensure accurate motor behavior. To date, studies on the vestibular cerebellum have predominately focused on passive vestibular stimulation, whereas in actuality most stimulation is the result of voluntary movement. Accordingly, I also consider recent research exploring these computations during active self-motion and emerging evidence establishing the cerebellum's role in building predictive models of self-generated movement. [ABSTRACT FROM AUTHOR]