Imagine you’re driving on a road with no signs. How do you know if you’re going straight or turning? Well, your brain relies on different signals to figure it out. Scientists have discovered that older adults sometimes struggle with this perception, which can increase their risk of falls. But there’s good news! A recent study found that a special kind of training, called multisensory visual-vestibular training, can actually improve our ability to estimate our heading (the direction we’re moving) using our vision. The training works by giving participants feedback on their judgments as they navigate through virtual environments. And guess what? The results showed that both younger and older adults saw improvements in their heading perception after the training. In fact, some older adults who couldn’t distinguish their heading at all before the training were able to do so afterward, just like their younger counterparts! While the training didn’t have an impact on standing-balance performance, it’s exciting to think about how this research could help improve self-motion perception in the real world, like navigating without clear signs. So, if you’re curious about how this multisensory training works and want to find out more about the study, go ahead and dive into the research!

Self-motion perception (e.g., when walking/driving) relies on the integration of multiple sensory cues including visual, vestibular, and proprioceptive signals. Changes in the efficacy of multisensory integration have been observed in older adults (OA), which can sometimes lead to errors in perceptual judgments and have been associated with functional declines such as increased falls risk. The objectives of this study were to determine whether passive, visual-vestibular self-motion heading perception could be improved by providing feedback during multisensory training, and whether training-related effects might be more apparent in OAs vs. younger adults (YA). We also investigated the extent to which training might transfer to improved standing-balance. OAs and YAs were passively translated and asked to judge their direction of heading relative to straight-ahead (left/right). Each participant completed three conditions: (1) vestibular-only (passive physical motion in the dark), (2) visual-only (cloud-of-dots display), and (3) bimodal (congruent vestibular and visual stimulation). Measures of heading precision and bias were obtained for each condition. Over the course of 3 days, participants were asked to make bimodal heading judgments and were provided with feedback (“correct”/“incorrect”) on 900 training trials. Post-training, participants’ biases, and precision in all three sensory conditions (vestibular, visual, bimodal), and their standing-balance performance, were assessed. Results demonstrated improved overall precision (i.e., reduced JNDs) in heading perception after training. Pre- vs. post-training difference scores showed that improvements in JNDs were only found in the visual-only condition. Particularly notable is that 27% of OAs initially could not discriminate their heading at all in the visual-only condition pre-training, but subsequently obtained thresholds in the visual-only condition post-training that were similar to those of the other participants. While OAs seemed to show optimal integration pre- and post-training (i.e., did not show significant differences between predicted and observed JNDs), YAs only showed optimal integration post-training. There were no significant effects of training for bimodal or vestibular-only heading estimates, nor standing-balance performance. These results indicate that it may be possible to improve unimodal (visual) heading perception using a multisensory (visual-vestibular) training paradigm. The results may also help to inform interventions targeting tasks for which effective self-motion perception is important.

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