ABSTRACT
Recent experiments on the interplay between mental activity and postural stability have raised questions about dual-task performance and postural control. Some studies found that postural stability is degraded while dual-tasking, while other studies found the opposite, leading to debates regarding the influence of supra-postural cognitive tasks and processing capacity limitations on postural control. Researchers had participants perform easy and difficult versions of a visuo-spatial cognitive task while standing with feet together (a less stable stance) or apart (more stable) under instructions to simply stand relaxed or to explicitly minimize postural sway. Participants stood on a Bertec force platform under blocked and counterbalanced instruction conditions of explicitly minimizing postural sway or standing relaxed. In both conditions participants were asked to avoid large movements, keep their arms at their sides, and look straight ahead at a computer monitor that was used for the cognitive task.
