[Changes in the cortical electrical activity during the formation in man of a visual set].

The EEG spectra were studied in 75 healthy adult patients during formation, actualization, and extinction of the visual set. In the group of subjects which had formed the stable set, the spectral power in the alpha band was higher and that in the delta and theta bands lower than in the group of subjects with unstable set. In the course of the experiment, such relationships remained basically the same. These findings suggest that the subjects who had the longer mismatch between the unconscious "internal image" and the real stimuli presented in a new situation (i.e., the subjects with the stable set) were closer to the state of physiological rest.