[One solution to the problem of basic psychophysical law and sensory scaling]

One of the central problems of psychophysics has been considered, namely, the problem of existence and uniqueness of the fundamental psychophysical law and direct sensory scaling. Based on the stochastical model of stimulus processing it was concluded that the Stevens' law should be regarded as the fundamental psychophysical law. A method for analytical description of direct sensory scales has been suggested. It is shown that two principal branches of psychophysical research--sensory sensitivity and psychophysical scaling--are naturally combined by the proposed stochastical perception model forming a unified psychophysical science.