[The reward impact on the performance of verbal creative tasks: behavioral and EEG effects]

The aim of this study was to compare the effects of stimulating originality verbal instruction (IN1) and monetary reward (IN2) on originality of solutions of a verbal creative task and EEG-correlates of activity, determined on the basis of biopotentials power mapping in the frequency range 4-30 Hz. Right-handed students (10 men and 10 women) took part in experiment. An increase of solutions originality under the influence of monetary reward was revealed. At the promise of monetary reward in comparison with IN1, there was a global increase of the task-related theta2 power. Common to the teta1, 2 and alpha2 bands was increase in hemispheric asymmetry of these rhythms power with higher values in the right hemisphere of the brain. These changes have been observed already in the background EEG after IN2 and testify that generalized changes in hemispheric asymmetry provide the preparatory state after the promise of monetary reward. Regional brain activity changes were associated with beta2 rhythm. Under IN2 in comparison with IN1 the task-related power decreased in all posterior electrode sites except for frontotemporal. Reward-related EEG changes were more typical for men. In men only, promised monetary reward increased theta2 asymmetry and task-induced alpha power. Our results suggest that promise of monetary reward for creative thinking can increase verbal creativity. Gender differences in the reward-related EEG power changes show that men and women differ in neurophysiologic mechanisms that underlie increase of creativity.