[Human cognitive space: coincidence of the models, built on base of EEG rhythms and psychometric measurements]

Earlier it was shown that the specific rhythmical EEG patterns appear during solution of the particular cognitive tasks, such as spatial and verbal ones. In this study not only basic, but also mixed, intermediate cognitive tasks were used. The aim was to estimate the similarity and the difference between EEG spectra during performance of the whole line of the thinking operations. The distances between EEG spectra were calculated in this base. We could see that these distances formed the arranged space where the spatial, imaginative and verbal thinking types found their logical position along the appropriate coordinate axes forming the model of cognitive space. Furthermore, though the EEG spectra varied across subjects, the distances between these spectra were rather similar. Thus, the cognitive map was almost invariant to particular spectral data. The same tasks were then presented to professional psychologists. Using the subjective scaling technique, they appointed the position of the tasks in the spatial, imaginative and verbal scales. These measurements were then used to build the subjective cognitive space map. The maps got via brain rhythms analysis and subjective scaling appeared to be practically identical. The data show that the thinking process is indeed encoded in brain rhythms.