High Phase Synchronization in Alpha Band Activity in Older Subjects With High Creativity.

Sou Nobukawa,Tetsuya Takahashi,Kanji Ueno,Kimiko Mizukami,Haruhiko Nishimura,Teruya Yamanishi

doi:10.3389/fnhum.2020.583049

Abstract

Despite growing evidence that high creativity leads to mental well-being in older individuals, the neurophysiological bases of creativity remain elusive. Creativity reportedly involves multiple brain areas and their functional interconnections. In particular, functional magnetic resonance imaging (fMRI) is used to investigate the role of patterns of functional connectivity between the default network and other networks in creative activity. These interactions among networks play the role of integrating various neural processes to support creative activity and involve attention, cognitive control, and memory. The electroencephalogram (EEG) enables researchers to capture a pattern of band-specific functional connectivity, as well as moment-to-moment dynamics of brain activity; this can be accomplished even in the resting-state by exploiting the excellent temporal resolution of the EEG. Furthermore, the recent advent of functional connectivity analysis in EEG studies has focused on the phase-difference variable because of its fine spatio-temporal resolution. Therefore, we hypothesized that the combining method of EEG signals having high-temporal resolution and the phase synchronization analysis having high-spatio-temporal resolutions brings a new insight of functional connectivity regarding high creative activity of older participants. In this study, we examined the resting-state EEG signal in 20 healthy older participants and estimated functional connectivities using the phase lag index (PLI), which evaluates the phase synchronization of EEG signals. Individual creativity was assessed using the S-A creativity test in a separate session before the EEG recording. In the analysis of associations of EEG measures with the S-A test scores, the covariate effect of the intelligence quotient was evaluated. As a result, higher individual S-A scores were significantly associated with higher node degrees, defined as the average PLI of a node (electrode) across all links with the remaining nodes, across all nodes at the alpha band. A conventional power spectrum analysis revealed no significant association with S-A scores in any frequency band. Older participants with high creativity exhibited high functional connectivity even in the resting-state, irrespective of intelligence quotient, which supports the theory that creativity entails widespread brain connectivity. Thus, PLIs derived from EEG data may provide new insights into the relationship between functional connectivity and creativity in healthy older people.

Highlights

Creativity is the fundamental ability to produce novel and appropriate work (Runco and Jaeger, 2012; reviewed in Sternberg, 1999; Amabile, 2018)
We aimed to evaluate the functional connectivity of the brain in the resting state in healthy older participants using the phase lag index (PLI) extracted from EEG signals and to examine the relevance of this connectivity to individual creativity
We examined the brain’s resting-state functional connectivity, as estimated by the PLI of EEG signals in healthy older participants, and its relevance to individual creative ability, taking the level of intellectual functioning into account

Summary

Introduction

Creativity is the fundamental ability to produce novel and appropriate work (Runco and Jaeger, 2012; reviewed in Sternberg, 1999; Amabile, 2018). Recent neuroimaging studies have identified various brain regions as necessary for the emergence of creativity (reviewed in Arden et al, 2010; Dietrich and Kanso, 2010; Fink and Benedek, 2014; Boccia et al, 2015; Pidgeon et al, 2016; Stevens and Zabelina, 2019) Some of these studies have employed the electroencephalogram (EEG) to capture neural activity that reflects various brain functions specific to the different physiologically relevant frequency bands, by exploiting this method’s advantageously fine temporal resolution (Klimesch et al, 2007). EEG studies have demonstrated alterations in frequency-band-specific neural activity during creative activity and have predicted performance in tasks that test creativity (Grabner et al, 2007; Bazanova and Aftanas, 2008; Fink and Neubauer, 2008; Danko et al, 2009; Fink et al, 2009; Razumnikova et al, 2009; Volf and Tarasova, 2010; Rominger et al, 2019; reviewed in Fink and Benedek, 2014; Pidgeon et al, 2016; Stevens and Zabelina, 2019)

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Conclusion