Abstract
Almost 40 years ago, it was shown that cells along the visual pathways (e.g., superior colliculus) respond preferentially when an auditory stimulus accompanies a visual stimulus (i.e., superadditive response: see Meredith & Stein, 1986). At the same time, it was also first shown that humans can make smooth hand trajectory corrections to a visual target jump (i.e., Goodale et al., 1986). From an ecological perspective, there are visual stimuli that require changes in a limb trajectory correction and are also accompanied by auditory stimuli (e.g., puck deviated by a stick). However, to our knowledge, it has yet to be shown if hand trajectory corrections to a target jump differ or not when an auditory stimulus accompanies a visual target jump. As a result, we tested the contribution of auditory cues to corrections for a visual target jump gap. Participants performed reaches to an initial 30 cm target, which could randomly jump to a 27 cm or a 30 cm target after movement onset on half of the trials (see Tremblay et al., 2017). During one of the two blocks of trials, a tone—delivered by a piezo-electric device—accompanied the target jump. The order of the blocks was counter-balanced across participants. The key findings included significant trajectory correction amplitudes for closer target jumps only (i.e., 30 cm to 27 cm) and that movement endpoint variability was smaller with than without auditory cues. As such, the known neurophysiological benefits of bimodal stimuli are probably linked to more precise limb endpoint control mechanisms.
