AGE-DIFFERENCES IN VISUAL SENSORY INTEGRATION

Numerous authors have reported that elderly persons are more affected than young adults when submitted to reduced or conflicting sensory inputs conditions. These results, however, do not permit to evaluate whether the elderly suffer from a reduced peripheral sensibility or from a deficit in the central integrative mechanisms responsible for configuring the postural set. The present experiment evaluated the ability of elderly to reconfigure the postural set when submitted to successive reduced and augmented visual sensory conditions. Results showed that young and elderly subjects' sway dispersion increased when they were exposed to a reduced visual sensory condition (i.e., vision/no-vision transition). However, when exposed to augmented sensory condition (i.e., no-vision/vision transitions) young adults were able to adapt rapidly and reduced their sway dispersion whereas the elderly exhibited an increased sway dispersion. This inability to adapt to an augmented sensory condition suggest that elderly persons, in addition to a reduced peripheral sensibility, have a deficit with central integrative mechanisms responsible for reconfiguring the postural set.