Rapid Audiovisual Integration Guides Predictive Actions

Natural movements, such as catching a ball or capturing prey, typically involve multiple senses. Yet, laboratory studies on human movements commonly focus solely on vision and ignore sound. Here we ask how visual and auditory signals are integrated to guide interceptive movements. Human observers tracked the brief launch of a simulated baseball, randomly paired with batting sounds of varying intensities, and made a quick pointing movement at the ball. Movement endpoints revealed systematic overestimation of target speed when ball launch was paired with a loud versus a quiet sound, even though sound was never informative. This effect was modulated by the availability of visual information: sounds biased interception when ball presentation time was short. Continuous eye movements uncovered that sound affected interception within 125 ms of ball launch and revealed a correction of the sound-induced bias when more visual information was available. Our findings suggest that auditory and visual signals are integrated to guide interception and that this integration process must occur early at a site that receives auditory and visual signals within an ultrashort timespan.