Creativity related cortex activity in the remote associates task.

The involvement of different oscillating neuronal systems during verbal creative thinking was investigated by multi-channel EEG measuring. The remote associates task (RAT) as a model of creative thinking in comparison to the resting condition and the simple associates task (SAT) was used. The EEG coherence along with spectral power density estimates were evaluated in each of the six frequency bands in 4-30 Hz range. We have found out RAT-related EEG changes mainly in the theta1, alpha1, alpha2 and beta2 bands. The RAT-induced cortical activation was differed from the SAT-induced EEG pattern by (i) widespread enhancement of power and coherence in the beta2, (ii) the theta1 power increase in the frontal cortex, and (iii) increased desynchronization of the alpha1,alpha2 mainly over posterior cortex together with the alpha1 coherence decrease in the prefrontal sites. Originality scores of the verbal associates positively correlated with an increase of coherence focused in the fronto-parietal regions of both hemispheres in the beta2 and in the left parieto-temporal loci in the alpha1. Additionally, more original responses positively correlated with amplitude of the alpha1 mostly in the left hemisphere. We propose that widespread cortical integration of multi-component internal processing has been simultaneously mediated during creative verbal thinking. The selectively distributed theta, alpha, and beta oscillations reflect intra- and inter-hemispheric communication networks with different functional relations to the RAT solving. The theta1 and alpha1 rhythms seem to specifically relate to top-down information processing such as deliberate sustained attention and working-memory-retention during defocused attention, respectively, whereas larger interregional synchrony in the beta2 band may mediate 'differential' attention to diffusely activating alternative meanings of words and remote associates from coarse semantic coding.