Changes in Background EEG Activity after Creative Task in Aged Adults

Cognitive training is considered as an effective intervention for slowing cognitive decline, however single-domain training programs have shown limited transfer to untrained tasks. Complex cognitive training has a potential to yield broader transfer effect. Given that creative thinking involves variety of cognitive subprocesses, creative tasks may be useful as a complex training paradigm. In line with this assumption, creative engagement has a neuroprotective effect in older subjects, improving mental health and well-being. However, neural mechanisms underlying the effect has remained unknown. Evidence suggests that post-task changes in resting-state brain activity may be detected in regions involved during training. The current study was aimed to reveal changes in electroencephalographic (EEG) activity during creative task performance and to identify whether those activity patterns persist in the baseline EEG after the end of a creative session. EEG was registered in 25 elderly ( $64\pm 6$ years) high-functioning subjects before, during and after creative problem solving, consisting of 30 verbal and 30 figural tasks. Current source density estimates and subsequent statistical contracts using statistical non-parametrical mapping (SnPM) were calculated via LORETA package. We found a significant increase of spectral density from pre- to post-task interval in theta-gamma frequency bands. The effect was localized in parieto-occipital cortex, overlapping with the region showing synchronization during the tasks performance. Observed changes in resting-state EEG activity may be considered as an indicator of use-dependent neuroplasticity.