The integration of visually-guided interception with balance

"Fast interceptive movements highlight human sensorimotor flexibility, surpassing that of robots. We can rapidly correct hand trajectories (less than 100 ms) for moving objects, even without conscious awareness, suggesting sub-cortical circuitry. Such fast visuomotor responses also guide stepping onto a moving target. However, balance-also largely sub-cortical-may be threatened by these quick adjustments. For instance, catching a ball shifts the centre of mass, but we rarely fall. How the brain integrates these two requirements-reaching and balancing-remains unclear, as attempts to replicate such control in bipedal robots often fail.
We aim to investigate the integration of balance and visually guided interception, the underlying neural circuitry, and the effect of ageing. Using techniques from Biomechanics, Neurophysiology, and Robotics, we will employ virtual reality to present moving targets and subtly manipulate the relationship between hand and target motion. Limb trajectory data will be processed in real-time to alter visual feedback, while ground reaction forces and full-body motion capture track balance.
First, we will determine the limits of balance-interception integration in young healthy individuals-at what point do they fall? We will then use Transcranial Magnetic Stimulation (TMS), Electromyography, and H-reflexes to identify the roles of cortical and sub-cortical brain areas. This knowledge may also inform rehabilitation strategies for balance impairments following brain injury.
Finally, we will study older adults to assess how neural degeneration affects the combined interception and balance system, and whether deficits in this integration increase fall risk. Our findings will advance understanding of fundamental human sensorimotor processes and inform future interventions for fall prevention."