The Yerkes-Dodson law: the problem of the content of variables

The author discusses the problem of the content of variables, the links between which are described by the Yerkes-Dodson law, focusing on the interrelation of the notions of stimulation, activation and motivation, which constitute the most common interpretations of the independent variable, as well as the notions of efficiency and productivity pertaining to the dependent variable. On the basis of a number of known theoretical approaches and with reference to an activity model of emotions, the author has formulated a hypothesis about two optimums of stimulation and made an attempt to integrate the pictures of the place and interaction of the existing variants of the dependent and independent variables according to the first law of Yerkes-Dodson.