In a linear system, visual scene motion evokes body sway at just those frequencies contained in the scene motion. We predicted a distortion using simulations, where body sway is evoked at frequencies NOT contained in the scene motion. This non-intuitive prediction was confirmed in experiments.

A typical behavior is that subjects sway increases less than proportional when increasing the movement amplitude of the visual reference: the 'gain' (amplitude ratio between body sway and stimulus) is reduced with increasing stimulus amplitude (Model fit left-to-right).

We implemented this mechanism in a closed-loop balance control model and compared its behavior with the sway responses of 24 subjects viewing a moving visual screen in a virtual reality head-mounted display.

The magic comes in, when assuming that the RFM reconstruction is blocked at small velocities and corrects (= is added to) the visual self-motion signal when exceeding a certain velocity threshold.
Why magic? It explains human behavior related to context dependent changes in sensory contributions.

In our new paper, we present evidence that the CNS continuously estimates the movement of the visual reference by comparing visual to other sensory cues. This reconstruction of Reference Frame Motion (RFM) happens in velocity. Why?

Is it me, or the train moving?
We use vision to maintain balance. Just close your eyes while standing on one leg and you typically feel less stable. But if we use vision, how come we do not fall when looking at a moving visual reference, e.g. a train?
📈🧠🧪
#sensorimotor #balance #BiomechSky

When the internal review process is the most rigorous, you mostly get helpful reviewer comments - and sometimes this. Thank you reviewer #2 😎

Big day on our journey. Today we had the first vestibular patient testing our newest Augmented Reality AVOC device for Fall prevention. 🧵
#VRcademicSky #XR #balance #FallPrevention 🧠🧪

The idea is simple: vision improves balance, but only when available. We want to use AR to make sure people always have a sufficiently rich visual reference for balance. Visual orientation will be maintained, e.g. when turning in front of a white wall, making a fall less likely.
#VRresearch