Influence of Visual Feedback on Roll Tilt Perceptual Training.

ABSTRACT

HYPOTHESIS: We hypothesized that the addition of visual feedback during roll tilt perceptual training would yield a significant reduction in vestibular perceptual thresholds relative to a control group. BACKGROUND: We previously showed that roll tilt vestibular thresholds could be improved through a perceptual training protocol that used a simple auditory cue. Variability in training outcomes within the treatment group suggested that an auditory cue alone may be suboptimal for improving self-motion perception. METHODS: In 10 healthy adults, roll tilt vestibular thresholds, quantifying the smallest motion that can be reliably perceived, were measured before ("pretraining") and after ("posttraining") a training protocol designed to improve roll tilt perception. The protocol included 1,300 trials of 0.5 Hz whole-body roll tilt over 5 days, with participants being given both an auditory cue ("correct' vs. "incorrect') and visual feedback (viewing a stationary visual scene) after indicating their perceived direction of tilt. A control group (N = 10) underwent only the "pretraining" and "posttraining" assessments. RESULTS: The training group showed an average decrease in roll tilt vestibular thresholds of 1.7% ± 56%, with training outcomes varying widely. Three individuals showed an average increase in roll tilt thresholds of 69.7%, whereas the remaining seven adults showed an average decrease in thresholds of 32.3%. CONCLUSION: These data show that visual feedback during roll tilt perceptual training leads to heterogenous outcomes, but in a subset of individuals, it may lead to improvements in perceptual precision. Additional work is needed to define the optimal training parameters, including feedback schema, before investigating potential clinical applications.