The human visual organ has the function of sensing the light and color of external objects. The wavelength range of visible light is generally 380nm (nanometer) to 780nm, which is called the visible spectrum. In the visible spectral range, different wavelengths of radiation make people feel different colors In general, 700nm is red, 580nm is yellow, 510nm is green, 470nm is blue, and 400nm is purple. The above phenomenon shows? ["People's feelings about things are the result of their own physiological activities.", 'The physiological threshold of human organs is the limit of human cognitive ability.', 'Human feelings include the selection, processing, and transformation of external information.', 'People can only recognize the feeling formed by external objects acting on the senses.']