Figure 1

Length of CoP displacements. The graphs show the mean CoP displacement over time in the different experimental conditions for the control subjects (left panel) and the deafferented subject (right panel). As the control subjects were remarkably stable while seated in all experimental conditions, the different traces are superimposed. The deafferented subject maintained a relatively stable seated posture with the eyes open. Closing the eyes markedly deteriorated her stability, especially when she had the head unconsciously turned towards a shoulder. Electric stimulation of the vestibular apparatus when the deafferented subject had the eyes closed allowed her to roughly recover the body stability she had with the eyes open. See Additional file 1: Table 1 for the statistical analyses.