Temporal auditory capture does not affect the time course of saccadic mislocalization of visual stimuli.
Irrelevant sounds can "capture" visual stimuli to change their apparent timing, a phenomenon sometimes termed "temporal ventriloquism". Here we ask whether this auditory capture can alter the time course of spatial mislocalization of visual stimuli during saccades. We first show that during saccades, sounds affect the apparent timing of visual flashes, even more strongly than during fixation. However, this capture does not affect the dynamics of perisaccadic visual distortions. Sounds presented 50 ms before or after a visual bar (that change perceived timing of the bars by more than 40 ms) had no measurable effect on the time courses of spatial mislocalization of the bars, in four subjects. Control studies showed that with barely visible, low-contrast stimuli, leading, but not trailing, sounds can have a small effect on mislocalization, most likely attributable to attentional effects rather than auditory capture. These findings support previous studies showing that integration of multisensory information occurs at a relatively late stage of sensory processing, after visual representations have undergone the distortions induced by saccades.
Binda
Paola
P
Department of Psychology, Università Vita-Salute San Raffaele, Milano, Italy. p.binda1@in.cnr.it
Morrone
M Concetta
MC
Burr
David C
DC
D000161:Acoustic Stimulation / Q000379:methods; D001288:Attention / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D010470:Perceptual Masking / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D012438:Saccades / Q000502:physiology*; D013017:Sound Localization / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*