[Brain mechanisms of imagination during verbal creative problem solving]

In the present study, EEG spectral analysis was used to examine the brain mechanisms of imagination in student actors and student non-actors under three experimental conditions: when subjects created a coherent story based on a presented picture (STORY), listed the details of the presented picture (DETAIL) and executed simple calculation while they looked at neutral background (COUNT). Statistical comparison of STORY and DETAIL conditions revealed significantly higher spectral power in alpha1 (7.5-10 Hz) and alpha2 (10-12.5 Hz) bands in the most of investigated cortical areas in actors and non-actors. By contrast, in comparisons STORY-COUNT and DETAIL-COUNT significantly lower spectral power in the same frequency bands in all investigated cortical areas in both groups was obtained. The most prominent differences in comparison STORY-DETAIL were revealed over the central parietal area. The most prominent differences in comparisons STORY-COUNT and DETAIL-COUNT were revealed mainly over the occipital areas. These EEG changes were found in both groups of subjects. Taking this fact into account we consider parietal areas to be stable element of the brain system which maintain verbal creativity in actors and non-actors. The discussion of our results with respect to those obtained in previous studies leads to conclusion that parietal areas are involved into the mechanism of selective inhibition of visual information processing during imagination.