On the cognitive penetrability of posture control

TLDR

Postural sway increases with age and is linked to reduced peripheral sensibility in visual, vestibular, and proprioceptive systems. The study examined whether micropostural adjustments for balance require cognitive processing. Young and older adults performed an auditory reaction‑time task while standing on a force platform under varied vision and surface conditions, with stimuli presented at central or eccentric center‑of‑pressure positions to assess whether eccentricity demands more attention. Results showed that reduced sensory information made the postural task harder for older adults, increasing their reaction times and indicating greater attentional load.

Abstract

Abstract Postural sway increases with age. The decreased stability associated with postural sway often has been related to the reduced peripheral sensibility in the visual, vestibular, and proprioceptive systems. We examined whether the micropostural adjustments necessary for maintaining balance also require some cognitive processing. Young and older subjects were submitted to an auditory reaction time task while maintaining an upright posture on a force platform. The auditory stimuli were presented randomly when subjects were in a central or in an eccentric less stable postural position in four conditions of vision/surface. If the postural adjustments require some cognitive processing, a more eccentric position of the center of foot pressure (COP) would require more attention than a stable position of the COP because when an eccentric position is identified, a corrective response subsequently needs to be selected, programmed, and executed. The visual and surface conditions were altered to determine if additional attentional resources need to be allocated to the postural task when there is a reduction of the sensory information available. Results showed that as the sensory information decreased, the postural task became increasingly difficult for the elderly and required more of their attentional capacity (as indexed by increases in reaction time).