A posture reflex evoked by the virtual self-moving condition

To investigate the cognitive aspects of posture control under the apparent force condition generated by auditory stimulation, body sway fluctuation was measured with healthy adult subjects. As an experimental stimulation, an increasing tone for the left ear and a decreasing tone for the right ear were used.. Subjects felt that the sound source was moving from right to left under an eyes closed condition. On the contrary, subjects who were shown a moving image of a natural scene which was interlocked to the auditory stimulus before the experiment (cognitive preparation), they felt themselves moving from a left to right direction. In this experiment, body sway was measured with and without the cognitive preparation. Results showed that the center of gravity biased to the opposite direction of subjective movement of the sound source with cognitive preparation. Without cognitive preparation, the center of gravity biased in the same direction of subjective movement of the sound source. It suggests that the higher level posture control reflex was observed in the cognitive condition without any sensory input from the muscle receptors.