P300 and psychophysiological analysis of the structure of behavior

P300 wave was analyzed on the basis of comparison between brain potentials, the structure of behavior and single unit activity within the signal detection task through experiments with humans and animals. The similarity of the late positive components following detected light flashes in humans and rabbits, identified as P300, permitted the use of data concerning single unit activity. The analysis of single unit activity in the visual and motor cortex of rabbits demonstrated that the sequence of behavioral stages in signal detection is based on different sets of units. There is a strong correspondence between the change of set and the P300 development. Since the activity of certain units in behavior reflects the realization of certain functional systems, the modification of the sets of activated units indicates the transformation of the composition of functional systems of different hierarchical levels during the change of behavioral stages. This is the basis for our suggestion that P300 reflects the process of reorganization of the structure of the behavior which is responsible for the transition from one stage of behavior to another.