Regularity and randomness in ageing: Differences in resting-state EEG complexity measured by largest Lyapunov exponent

The loss of complexity in ageing hypothesis (LOCH) has found support from EEG studies, most which adopted signal-domain measures. present study the largest Lyapunov exponent (LLE) to measure a nonlinear dynamical systems perspective. A total 144 participants were included and divided into young, young-old old-old groups. Both sensor-space source-space results showed significantly lower LLE for older than younger adults. age-related differences region-dependent, being prominent frontal region, followed by bilateral temporal regions. occipital region non-significant differences. Significant reduction posterior cingulate was also observed virtue analysis. We evaluated relationships between other intriguing result negative correlation Lempel-Ziv (LZC). decrease indicated higher regularity dynamics, while LZC randomness signal domain. new findings LOCH demonstrating simultaneous increase randomness.