extension reading: the American version of the classic "visual cliff" experiment
a visual cliff designed by American psychologist Walker and Gibson is an experimental device used to observe the depth perception of the baby. The visual cliff experiment is later known as one of the classical experiments in developmental psychology.
experimental steps: the so-called "sight cliff" refers to a platform like a table with a thick glass plate on the platform, the platform is divided into two halves in the middle, and half the top is covered with a red and white lattice pattern as "shallow", and the other half of the lattice is placed about 150 centimeters under the glass (highly adjustable), on this side. For the "deep side". In the experiment, the infant was placed on the middle line near the shallow side of the platform, and the mother stood on the deep side of the cliff to summon the child. If the baby climbed to the "deep side" without any consideration, the baby could not judge the depth of the baby. If the baby refused to climb to the deep side, it showed that the baby was capable of deep perception.
experimental principle: the main point of experimental design is to exclude the influence of past experience on the subjects. If the past experience is excluded, the result of the test is the same as that of the non exclusion test, then it can prove that there is no need for perception. With the support of experience, the ability to perceive depth and to avoid falling from height is automatically generated, rather than the product of experience.
experimental results: the 2-3 month old baby's abdomen was placed down on the side of the "visual cliffs" to find that the baby's heartbeat speed would slow down, indicating that they had experienced the depth of the object; when the 6 month old baby was placed on the glass board, the mother had to call the baby on the other side and found that the baby would not hesitate to crawl. There is no illusion of depth, but I do not want to climb over the side that looks like a cliff, even if my mother is crying on the opposite side. This seems to indicate that the baby has a depth perception, but this depth perception is innate, or has been learned in the months after birth, and is not yet conclusive.