When you go for a walk, how does your brain know the difference between a parked car and a moving car? This seemingly simple distinction is challenging because eye movements, such as the ones we make when watching a car pass by, make even stationary objects move across the retina—motion that has long been thought of as visual "noise" the brain must subtract out.
Now, researchers at the University of Rochester have discovered that instead of being meaningless interference, the visual motion of an image caused by eye movements helps us understand the world. The specific patterns of visual motion created by eye movements are useful to the brain for figuring out how objects move and where they are located in 3D space.
"The conventional idea has been that the brain needs to somehow discount, or subtract off, the image motion that is produced by eye movements, as this motion has been thought to be a nuisance," says Greg DeAngelis, [...] "But we found that the visual motion produced by our eye movements is not just a nuisance variable to be subtracted off; rather, our brains analyze these global patterns of image motion and use this to infer how our eyes have moved relative to the world."
[...] "We show that the brain considers many pieces of information to understand the 3D structure of the world through vision, including the patterns of image motion caused by eye movements," says DeAngelis. "Contrary to conventional ideas, the brain doesn't ignore or suppress image motion produced by eye movement. Instead, it uses this image motion to understand a scene and accurately estimate an object's motion and depth."
This research has important implications for understanding visual perception, which informs how the brain interprets everyday activities like reading and recognizing faces. But it could also provide insight and new applications for visual technologies, such as virtual reality headsets.
"VR headsets don't factor in how the eyes are moving relative to the scene when they compute the images to show to each eye. There may be a stark mismatch between the image motion that is shown to the observer in VR and what the brain is expecting to receive based on the eye movements that the observer is making," says DeAngelis. This could be what causes some people to experience motion sickness while using a VR headset.
Journal Reference: Xu, ZX., Pang, J., Anzai, A. et al. Flexible computation of object motion and depth based on viewing geometry inferred from optic flow. Nat Commun 17, 1092 (2026). https://doi.org/10.1038/s41467-025-67857-4
(Score: 0) by Anonymous Coward on Wednesday April 08, @01:38AM (2 children)
Yeah. IMO the mind uses multiple images to construct 3D. Whether the multiple images come from eye movements or other movement is not the important point.
See also: https://en.wikipedia.org/wiki/Kinetic_depth_effect [wikipedia.org]
Heck many minds don't even need optical images to construct the 3D. We can even use our ears or other senses (touch). If we hear various echoes from a room (from snapping fingers, tongue clicks[1] etc), we can get a 3d "image" of the room, not a high res one of course but...
[1] https://en.wikipedia.org/wiki/Human_echolocation [wikipedia.org]
(Score: 2) by JoeMerchant on Wednesday April 08, @02:43AM (1 child)
> IMO the mind uses multiple images to construct 3D
The mind uses whatever it's given.
One technique of determining 3D depth is useful in moving fields - nearer things move bigger angular displacements than further things, math geeks use this in image processing to separate near from far objects as seen from moving cameras.
Also useful when you have a plurality of unladen African swallows flying in a uniform direction with varying distances from the observer, or similar situations. https://www.youtube.com/watch?v=uio1J2PKzLI [youtube.com]
🌻🌻🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Wednesday April 08, @03:11AM
>... math geeks use this in image processing to separate near from far objects as seen from moving cameras.
Sounds like a good opening for spoofing these "vision" systems. Just make a bunch of inflatables that look like normal things (cars, people on bikes, etc) that are scaled either up or down from normal sizes.