EEG complexity in relation to withdrawal motivation level

Abstract

The research was conducted on 17 healthy volunteers, who were divided into two groups, according to their motivation (withdrawal) level – one group with a high motivation level (10 persons) and one group with a middle motivation level (7 persons). EEG was recorded during both a resting state and intellectual task solving. Then EEG was analyzed, using the TISEAN package. Correlations were valuated for 8 EEG lead positions (symmetrical frontal, temporal, parietal and occipital lobes in the left and right hemispheres) with embedding dimension 5 10. Though we expected specific features, which depend on motivation level, in frontal areas, main effects were observed in parietal lobes. In both the high and middle motivation level groups, therewas a statistically significant increase in correlation dimension values in both parietal lobes. But in the group with middle motivation level, the correlation dimension value, which was lower in the right parietal lobe compared to those in the group with high motivation level (7,46 and 7,70 respectively), the effect was greater for the intellectual task (8,04 and 7,95 respectively). We hypothesize that complexity of electrical processes in the parietal cortex may depend on motivation level.