The study found that feedback signals that characterize visual perception characteristics dominate visual sensitivity adaptation.

On August 6, Nature Communications published online the latest research results from the Hesheng team at the National Key Laboratory for Brain and Cognitive Sciences at the Institute of Biophysics of the Chinese Academy of Sciences.
the study reveals the important influence of feedback signals in the visual cortical layer on the selective adaptation of orientation in visual perception.
is a common feature of the nervous system, especially the perceptive system.
the nervous system adapts to the dominant inputs in its environment to perform its best function.
, however, the symptoms of input stimuli in the cortical layer are usually modulation by feedback signals and sometimes inconsistent with the feed-on input status of stimuli.
the study aims to reveal the relative contribution of feed-forward and feedback signals in the visual cortical layer to visual adaptation.
study reveals through psychophysical experiments that the adaptation of human vision to the directional signal is dominated by the perceptic consciousness and not by the orientation of the retina input.
this conclusion was reached by measuring the positive adaptation effect of subjects after repeatedly watching the Flash-Grab effect.
Usually, when a person repeatedly watches a line that is slightly tilted toward a direction, the subsequent vertical line is perceived as a line tilted in the opposite direction, called the tilt after effect, and if the vertical line is viewed repeatedly, it does not cause a tilt effect on the vertical line.
when the direction of a line itself is vertical, but because the illusion effect makes it percepable into a tilted line, will it also cause tilt after effect? The Flash-Grab effect provides this way to clearly separate the input and percession directions of the lines, and in the Flash-Grab effect, lines rendered vertically are involuntarily sensed into lines that are significantly tilted.
The study used this as a visual stimulus caused by adaptation in the visual adaptation experiment to observe the tilt effect, the experimental results show that when the actual input of the line tilts towards the vertical, it does not cause the tilt after effect;
, the effect of visual tilt is determined by perception, not retina input orientation.
using high-resolution brain imaging, researchers found that the visual cortical symptoms of sensory orientation in the Flash-Grab effect depended largely on feedback signals.
Using 3T and 7T mm high spatial resolution functional magnetic resonance imaging, it has been found that there is a perceptorial orientation in the flash-Grab effect in the early visual cortical layer, which is more indicative of V2 and V3 than V1, and in V1, the surface is dominated by feedback signals. The signs are stronger than the middle and deep, and the electro-encephalographic records using millisecond time resolution show that the sensory orientation corresponding signals in the Flash-Grab effect appear in the late stages of the visual cortical information processing compared to the early stage of the forward feed-forwarding signal, and the above brain imaging results show that the indication of the perceptic orientation in the early visual cortical layer depends on the feedback signal.
The study used an optical illusion, the Flash-Grab effect, to separate the input and the perception-to-direction, and found that the tilting effect depended on the perception rather than the input orientation;
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