Auditory-Vestibulomotor Temporal Processing and Crossmodal Plasticity for Musical Rhythm in the Early Blind

The auditory dorsal stream (ADS) is a cortical brain network responsible for sensorimotor control and integration, including spatiotemporal processing. Although spatiotemporal movement of the head and body involves input from the vestibular system, and despite the wealth of evidence for the strong coupling between the vestibular and visual systems, very little is known about how vestibular information is integrated with auditory-motor inputs in the ADS. There is also no evidence addressing to what extent auditory-vestibulomotor integration is affected by early visual deprivation. Using functional magnetic resonance imaging and motion capture technology we show that in a task of sensorimotor temporal processing ( feeling the beat), the ADS includes an extension to parietoinsular vestibular cortex (PIVC) and to subcortical regions including basal ganglia and vestibular cerebellum. This circuit is engaged after sensorimotor synchronization training, during beat recognition, and is preserved in the early blind. The strength of activation of PIVC in the early blind correlates with a measure of lifetime physical spatial activity, suggesting that experience with vestibular stimulation via physical spatial activities might compensate for any negative effects of early blindness, and thus reinforcing the potential beneficial effects of mobility training. Finally, rhythmic entrainment provides an effective tool for studying auditory-vestibulomotor integration and music appreciation, and for developing music- and movement-based interventions for early blind individuals.