Cross-modal influences on perceptual organization were demonstrated using a display that combined a stimulus for auditory stream segregation with its visual apparent movement analogue. Both phenomena give rise to the perception of either one or two objects, depending on the rate of presentation of the stimuli. At slower rates, one object is perceived, while two are perceived at faster rates. Subjects indicated the stimulus onset asynchrony (SOA) between successive stimuli at which the perceptual shift occurred in each modality. Then visual and auditory stimuli were presented concurrently and subjects responded to the “target” modality sequence. Two intergroup separations for the nontarget stimuli were used. Distances were chosen, based on the subject’s calibration data, which represented one and two objects, respectively, at the stream segregation point for the target sequence. Segregation occurred at larger SOAs when the nontarget stimulation indicated two objects than when it represented one. This was true for both visual and auditory target sequences.
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