Attentional demands associated with the use of a light fingertip touch for postural control during quiet standing.

The purpose of the present experiment was to investigate whether and how using a light fingertip touch for postural control during quiet standing requires additional attentional demands. Nine young healthy university students were asked to respond as rapidly as possible to an unpredictable auditory stimulus while maintaining stable seated and upright postures in three sensory conditions: vision, no-vision and no-vision/touch. Touch condition involved a gentle light touch with the right index finger on a nearby surface at waist height. Center of foot pressure (CoP) displacements were recorded using a force platform. Reaction times (RTs) values were used as an index of the attentional demand necessary for calibrating the postural system. Results showed decreased CoP displacements in both the vision and no-vision/touch conditions relative to the no-vision condition. More interestingly, a longer RT in the no-vision/touch than in the vision and no-vision conditions was observed. The present findings suggest that the ability to use a light fingertip touch as a source of sensory information to improve postural control during quiet standing is attention demanding.