Spatialized sound influences biomechanical self-motion illusion ("vection")

Although moving auditory cues have long been known to induce self-motion illusions ("circular vection") in blindfolded participants, little is known about how spatial sound can facilitate or interfere with vection induced by other non-visual modalities like biomechanical cues. To address this issue, biomechanical circular vection was induced in seated, stationary participants by having them step sideways along a rotating floor ("circular treadmill") turning at 60°/s (see Fig. 1, top). Three research hypotheses were tested by comparing four different sound conditions in combination with the same biomechanical vection-inducing stimulus (see Fig. 1, bottom).