A person sees a relatively stable and “fixed” picture of the surrounding world, even with a rapid step or run due to the presence in the eyes of special cells that play the role of a kind of accelerometers and motion sensors.
“In any good camera there is a whole set of sensors that stabilize the picture when moving.In our body the same role is played by retinal cells and the vestibular apparatus that recognize the movements and rotation of the body.Otherwise, the picture would be smeared when walking or running and we did not Could see, but from the clarity of vision, of course, our life very often depends, “- says David Berson (David Berson) of Brown University (USA).
In recent years, scientists have found more evidence that the perceived picture and sounds of the surrounding world are not an objective picture of reality – our senses and the brain actively “edit” it, removing all unnecessary and interfering elements.
For example, recently, scientists have discovered that people do not hear the beating of their own heart because the brain filters out a signal that gets into the sound bark from the ears. Similarly, as many neuroscientists believed, our nervous system makes the picture in the eyes stable during walking and running, despite the fact that the position of the eyes and the pressure inside them constantly changes during movement.
Berson and his colleagues found that at least part of this “auto-adjustment” system of vision is not in the brain, but inside the eyes of a person and other mammals, watching the activity of different groups of nerve cells in the retina of the mouse eye. To do this, the authors of the article built in the DNA of its neurons special genes that made the cells glow when they activated and transmitted the signal to the brain.
As the neurophysiologist says, scientists have known for a long time about the existence of a special group of cells in the retina, the so-called DSGC-neurons, which react to the movement of the picture only in a certain direction. In the past, biologists believed that the behavior of these cells was rigidly dependent on their type and on what signals the vestibular apparatus provided them.
Observing the work of several thousand such cells in the eyes of mice, Berson’s team found out that in fact these cells work by themselves and that they all perform two identical tasks – they recognize the rotational and translational movements of the head and the whole body, monitoring the shifts in The position of certain objects in different parts of the field of vision. These cells directly control the muscles responsible for the rotation and movement of the eyes.
The data collected by these cells is subsequently used by the vision center in the brain in order to correct the perceived picture and make it clear, rather than smeared, in combination with signals from the vestibular apparatus or even without its participation.
How these cells work and how they recognize rotational and translational movements, scientists do not yet know, but they plan to understand how this happens in their next experiments, in which animals with binocular vision similar to human eyes will be studied.