A remote connection
The research, which has just been published in Current Biology, could eventually be used to diagnose balance disorders and help treat motion sickness or vertigo.
Until now the technique, which uses electrodes placed just behind peoples' ears and stimulates their nerves, has led people to lose their balance.
What Drs Richard Fitzpatrick and Jane Butler from the Prince of Wales Medical Research Institute (POWMRI) did differently was ask the volunteers to walk with the head in specific pre-calculated positions, facing either downwards or slightly upwards.
While blindfolded, the five female and five male subjects were able to be steered in different directions without affecting their balance. The control was accurate enough to allow them to be steered around the paths and obstacles in Sydney's Botanical Gardens for extended periods.
The researchers found that with a subject's head in another position, the same stimulus caused the person to lean in one direction or another but did not steer their walking.
The stimulus affects the semicircular canals, which are small receptors in the inner ear that detect head rotation. These are part of the vestibular system that assists in orientation and balance.
"We were effectively introducing a small signal of vertigo but at subclinical levels. Vertigo is the symptom of spinning that comes from the rotational receptors" said Dr Fitzpatrick. "We have shown that the brain can effectively break down this signal and that it uses it to control steering and balance."
The findings support fossil evidence of an evolutionary change in the human semicircular ear canals during the development of upright posture.
Collaborating with them in their research and an author on the paper is Dr Brian Day from Institute of Neurology at University College London.
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