The study aimed to reveal task-related differences in story creation with and without the mental effort of overcoming self-induced stereotypes. Eighteen right-handed subjects (19.3 ± 1.1 years old) created stories. The subjects reported the formation of story plot stereotypes (as we call them: self-induced) during self-regulated creative production, which had to be overcome with the instruction to continue the story. Creative task fulfillment (without formed stereotypes-first stage of creation) was characterized by a decrease in the wave percentages of 9-10 Hz, 10-11 Hz and 11-12 Hz frequencies and EEG desynchronization (decreases in EEG spectral power) in the theta (4-8 Hz), alpha1 (8-10 Hz) and alpha2 (10-13 Hz) frequency bands in comparison with the REST (random episodic silent thought) state. The effortful creation task (with overcoming of self-induced stereotypes-second stage of creation) was characterized by increases in waves with frequencies of 9-10 Hz, 10-11 Hz, 11-12 Hz in temporal, occipital areas and pronounced EEG synchronization in alpha1,2 frequency bands in comparison with the free creation condition. It was also found, that the participants with the higher originality scores in psychological tests demonstrated increased percentage of high frequencies (11-12 Hz in comparison with those who had lower originality scores. Obtained results support the role of alpha and theta frequency bands dynamics in creative cognition.
Keywords: EEG frequency; EEG spectral power; creative story generation; mental effort; self-induced stereotypes.