a branch of experimental psychology that studies the dependence of the magnitude of a sensation (a subjective experience that occurs in a certain sensory modality) on the intensity of the corresponding stimulus or stimulus (physical impact). In a broader sense, psychophysics is considered as the science of measuring the body’s reactions to external influences. It was founded by Gustav Theodor Fechner (Elements of Psychophysics, 1860), who formulated the basic psychophysical law that underlies the modern concepts of this discipline.