Researchers at the Institute of Science and Technology Austria (ISTA) have studied how the eyes and the brain process fast-moving scenes.
Their study, published in Nature Neuroscience, marks a step in understanding how mammals, including potentially humans, process vision during movement.
The researchers studied a part of the mouse brain called the ventral lateral geniculate nucleus (vLGN), which is like a small, egg-shaped structure deep in the brain. This area processes brain signals that control movement to reduce distortions in vision.
The vLGN works by blending different signals from the brain to create a corrective signal. It helps unblur images when the eye moves, making visual processing quicker. Think of it like filming a Formula 1 race where you need to reduce exposure time to avoid blurry footage. The vLGN does something similar, allowing us to see clearly even when we're moving. This happens very early in visual processing, before the information goes to parts of the brain that deal with complex visual features.
Previous research looked at how the brain corrects vision during quick eye movements, but those studies focused on later stages of visual processing. But since our senses deal with constant movement, early correction in the brain is crucial. The vLGN's function might have been missed before because researchers were looking at already corrected images in later brain stages.
Seeing realtime brain activity in mice wandering in virtual reality
To study this, the researchers used a special microscope for two-photon calcium imaging, allowing them to see brain activity in awake, behaving mice within a virtual reality setup. This helped them understand how the vLGN uses behavioral instructions to manage visual distortions.
“With this setup, we can look into the brain of a mouse and observe the activity of the vLGN nerves while the mice are wandering through a virtual world,” says research leader Maximilian Jösch in an ISTA press release.