The early plasticity of the nervous system is manifested by modifiability and compensatory properties. For example, if cells of the visual system are transplanted into other organ systems, the visual cells will change their function and play a new role with a new partner and perform well, but the transplantation time should be early, and after a certain sensitivity period, the transplanted cells will not only not play a new role, but also die. Here is a vivid example of the sensitivity of nerve cells to experience can be changed. 28 days old kitten, before the special visual experience, the visual cortex cells are sensitive to all directions of visual stimuli, if in the early postnatal visual sensitivity period to give it vertical stripes for 1 hour, this hour of experience can change the sensitivity of the visual cortex cells, later can only see the vertical direction of the stripes, the horizontal, oblique stripes are not sensitive. oblique stripes will not be sensitive. This training in the early postnatal period has the best effect, late, even if the training time up to 33 hours, the effect will not exceed the early training for 1 hour.