Visual direction perception is pulled toward direction of head rotation

In order to effectively navigate the world around us, we must be able to correctly attribute motion signals to a wide variety of sources, including ourselves. Previous research has examined how we accurately split visual motion signals into those caused by self-motion or object motion, however this misses the key fact that we are active observers in our environment. To understand how we successfully disentangle complex motion signals, we must investigate how active components of self-motion signals might influence visual motion perception. The current study utilises virtual reality (VR) technology to investigate perceived direction of visual retinal motion across two experiments during active head rotations. Experiment 1 investigates the influence of horizontal active head rotations on the perceived direction of motion for 16 motion angles spaced equally around 360°. Experiment 2 additionally manipulated the strength of visual motion signals in order to examine how vestibular and visual signals might be weighted when one sensory signal is unreliable. In both experiments, perceived direction of visual motion was consistently biased toward the direction of head rotation, demonstrating an influence of active movement on vision. In addition, directions of motion that were adjacent to the cardinal axes (e.g. ±22.5° from vertical/horizontal) were repelled away from the cardinal reference during head rotations and stationary conditions, indicating an additional effect of reference repulsion.