The effect of differing optic flow on steering behaviours during goal-oriented locomotion

The ability of healthy young individuals to accurately steer toward a virtual target while experiencing different foci of expansion (FOE) and target positions was examined with the use of a virtual reality task. Ten participants steered toward the virtual target with the use of mouse displacements while sitting or while changing their body orientation during over-ground walking. Net virtual errors showed that participants were able to accurately align themselves with the target despite having confounding visual information regarding FOE location and heading direction. Participants performed better in the mouse-driven task than the walking task. This may be attributed to the nature of the tasks that employ different degrees of freedom. Altogether, results support the use of this virtual reality-based paradigm to further investigate the contribution of altered visual self-motion processing and gait-related impairments on steering abilities in stroke and in the elderly.