Temporal and spatial dependency of the ventriloquism effect.

The perception of the spatial location of an auditory stimulus can be captured by a spatially disparate visual stimulus, a phenomenon known as the ventriloquism effect. This study investigated the temporal and spatial dependency of this illusion. In the temporal domain, only disparities of 50-100 ms were perceived as simultaneous, and disparities where the visual stimulus occurred before the auditory stimulus were more effective in creating the illusion. In the spatial domain, the illusion was elicited most strongly at spatial disparities below spatial discrimination thresholds. There was also a significant interaction between temporal and spatial disparities. These results indicate that both temporal and spatial parameters are critical in the perception of real world objects in extrapersonal space.