Mechanism of video compression detected in brain

It turns out that the brain effectively compresses the signal that comes from the organs of vision. Scientists from the Institute of Neural Computing at the Ruhr University (Germany) have shown that the visual cortex suppresses redundant information and conserves energy, transferring only the changes between the pictures. About the same methods are used in modern video codecs.

The illustration above shows how the primary visual cortex processes a sequence of images, one of which lacks vertical elements. In this case, the brain calculates the difference between full and incomplete images and in certain cases only transmits this difference (the third image).

To test the hypothesis, scientists recorded the responses of neurons in the cat's brain to demonstrate a sequence of images, such as plants, landscapes, and buildings. Two versions of images were created: the full version and the version without vertical / horizontal elements. When displaying images with a frequency of 33 Hz (33 images per second, approximately 30.3 milliseconds per frame), the maximum neuron activity was recorded, which depended linearly on the number of images. But when the speed of displaying images was reduced to 10 Hz (10 images per second, 100 milliseconds each), the activity of neurons decreased in the case of images with missing information. Scientists suggest that the cat's brain, having received time for data processing, made an energy-efficient solution to encode the difference between frames.
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Visualization of neurons on an area of ​​several square millimeters was carried out using a special ink that is sensitive to voltage. In case a pulse passed through a neuron, it began to glow.

Scientific work published in the journal Cerebral Cortex (free access).