Augmenting sensory-motor conflict promotes adaptation of postural behaviors in a virtual environment.

ABSTRACT

We present results from a series of studies that investigated how multimodal mismatches in a virtual environment modified postural response organization. Adaptation of motor commands to functional circumstances is driven directly by error signals. Thus, motor relearning should increase when performing in environments containing sensory mismatch. We hypothesized that kinematics of the response would be linked to specific characteristics of the sensory array. Sensory weighting was varied by 1) rotating the visual field about the talo-crural joint or the interaural axis, 2) adding stochastic vibrations at the sole of the foot, and 3) combining galvanic vestibular stimulation with rotations of the visual field. Results indicated that postural responses are shaped by the location of a sensory disturbance and also by the processing demands of the environmental array. Sensory-motor demands need to be structured when developing therapeutic interventions for patients with balance disorders.