  The purpose of the present experiment was to investigate whether the sensory
weighting of a plantar pressure-based, tongue-placed tactile biofeedback for
controlling posture could be subject to inter-individual variability. To
achieve this goal, 60 young healthy adults were asked to stand as immobile as
possible with their eyes closed in two conditions of No-biofeedback and
Biofeedback. Centre of foot pressure (CoP) displacements were recorded using a
force platform. Overall, results showed reduced CoP displacements in the
Biofeedback relative to the No-biofeedback condition, evidencing the ability of
the central nervous system to efficiently integrate an artificial
plantar-based, tongue-placed tactile biofeedback for controlling posture during
quiet standing. Results further showed a significant positive correlation
between the CoP displacements measured in the No-biofeedback condition and the
decrease in the CoP displacements induced by the use of the biofeedback. In
other words, the degree of postural stabilization appeared to depend on each
subject's balance control capabilities, the biofeedback yielding a greater
stabilizing effect in subjects exhibiting the largest CoP displacements when
standing in the No-biofeedback condition. On the whole, by evidencing a
significant inter-individual variability in sensory weighting of an additional
tactile information related to foot sole pressure distribution for controlling
posture, the present findings underscore the need and the necessity to address
the issue of inter-individual variability in the field of neuroscience.
