Dynamics of the spatial organization of cortical electrical activity during the formation and actualization of a cognitive set to facial expression.

The coherence functions of cortical electrical potentials were studied in 35 healthy adults in the alpha (8-13 Hz) and beta (14-25 Hz) ranges, recorded at the stages of formation and testing of a visual set to images of faces bearing different emotional expressions. At the set actualization stage, the frontal area showed significant increases in intra-and interhemisphere coherence of potentials in the alpha range and coherence of potentials between the frontal and temporal areas of the cortex in the right hemisphere. These analytical results support the suggestion that the formation and actualization of a set to emotional facial expression are predominantly associated with activity in the frontal areas of the cortex. This conclusion is based on the view that the extent of spatial synchronization of electrical potentials is a measure of the functional relationships between corresponding cortical areas and their cooperativity, and thus reflects the state of their activity.