Effect of auditory deprivation on adaptive locomotion: Interaction with lower visual field occlusion

Auditory stimuli have been suggested to play a role in adequately controlling movement; however, their influence is not fully understood, particularly regarding dynamic behaviors, such as adaptive locomotion. This study aimed to investigate whether auditory deprivation affects adaptive locomotion. In particular, we aimed to elucidate the role of the auditory sense in obstacle avoidance by manipulating the visual field, which provides crucial sensory information for movement control. Sixteen participants approached a 15-cm obstacle located 6 m away and stepped over it under four different conditions that combined two factors: the hearing condition controlled by wearing earmuffs with and without holes, and the lower visual field condition controlled by carrying opaque white and transparent boards. Spatiotemporal variables during the approach to the obstacle were measured using an electronic walkway, whereas foot clearance over the obstacle was assessed using a motion-capture system. Participants who experienced auditory deprivation and lower visual field occlusion demonstrated greater variability in step length when approaching the obstacle compared with the other conditions. The leading and trailing foot clearances were higher under lower visual field occlusion conditions. Furthermore, when participants were under conditions of auditory deprivation, greater variability was observed in the clearance of the leading foot. These results suggest that auditory information contributes to movement stabilization during adaptive locomotion. Our findings provide evidence that auditory and visual senses complement each other during motor actions, indicating that adaptive locomotion can be influenced by the integration of multiple sensory inputs.