These cues are combined to allow the brain to stabilize vision, maintain balance, and estimate head orientation. Vestibular inputs are processed in an inherently multimodal environment and are enhanced through integration with other sensory inputs including from the visual, auditory, and proprioceptive systems. Reduced temporal integration performance in patients with vestibular hypofunction may explain some symptoms associated with vestibular loss. These parameters were highly correlated for those with normal vestibular function and for patients with vestibular hypofunction. The relationship between sensitivity to whole body rotation and duration of the temporal window of visual-vestibular integration was examined using psychophysical techniques. NEW & NOTEWORTHY While spatial visual-vestibular integration has been well characterized, the temporal integration of these cues is not well understood. Even among normal functioning participants, a high correlation between TBW and vestibular thresholds was observed, suggesting that these perceptual measurements are sensitive to small differences in vestibular function.

A reduced ability to temporally combine sensory cues appropriately may provide a novel explanation for some symptoms reported by patients with vestibular deficits. The wide TBWs in vestibular-deficient participants compared with normal functioning participants indicate that peripheral sensory loss can lead to abnormal multisensory integration. Participants reported that the rotation onset needed to lead the light flash by an average of 80 ms for the visual and vestibular cues to be perceived as occurring simultaneously. Among all participants, TBW and vestibular thresholds were well correlated ( R 2 = 0.674, P < 0.001), with vestibular-deficient patients having higher thresholds and wider TBWs. Vestibular thresholds ranged from 0.7 to 16.5 deg/s and TBWs ranged from 13.8 to 395 ms. Vestibular perceptual thresholds to yaw rotation were characterized and compared with the TBWs obtained from participants who judged whether a suprathreshold rotation occurred before or after a brief visual stimulus. We investigated the hypothesis that vestibular deficits could disrupt temporal visual-vestibular integration by determining the relationships between vestibular threshold and TBW in participants with normal vestibular function and with vestibular hypofunction. To be interpreted as being associated in time, these cues must occur within a limited time window, referred to as a “temporal binding window” (TBW). A single event can generate asynchronous sensory cues due to variable encoding, transmission, and processing delays.

Vestibular and auditory system