Auditory-visual interactions and the correspondence between perceived auditory space and perceived visual space.

Changes in the physical rate of a clicking or fluttering sound caused changes in the rate at which a simultaneously viewed light appears to flicker, even though the physical flicker rate remains constant. Perceived flicker rate increases in response to a rate of change of flicker frequency, and this auditory 'driving' does not depend on whether the auditory and visual sources have the same location. Visual evoked potentials do not correlate with 'driving'. Thus, the effect of auditory flutter upon perceived visual frequency is not due to the properties of Morrell-type bimodal neurons, nor does it reflect the activities of neurons responsible for maintaining correspondence between perceived auditory space and perceived visual space. The effect is possibly due to modification of a subjective criterion rather than, as previously suggested, to the entrainment or time-locking of physiological signals in the visual pathway.