Related Experiment Video
Updated: Jul 16, 2026
Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy
Published on: August 5, 2014
Three-order interactions in the alpha band of default mode network EEGs based on O-information rate: insights from
Hamed Azami1,2,3, Yuri Antonacci4, Daniel M Blumberger1,2,3,5
1Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 1025 Queen St W, Toronto, ON, M6J 1H1, Canada.
Background:
Alpha-band default mode network (DMN) connectivity declines with aging and Alzheimer's disease (AD), yet most electroencephalography (EEG) connectivity studies used pairwise (two-order) measures, such as mutual information rate (MIR). We leveraged O-information rate (OIR) to quantify three-order interactions and to separate redundant from synergistic information processing across frontal, temporal, and parietal DMN regions. We hypothesized that, extending established findings of reduced pairwise connectivity, (i) OIR (and its components) would be reduced in older versus younger adults and in AD versus healthy controls (HC); (ii) combining MIR with OIR would improve classification compared with MIR alone; and (iii) OIR measures would correlate positively with global cognition (as assessed by the Montreal Cognitive Assessment (MoCA)).
Methods:
Resting-state EEG from two samples-healthy adult lifespan aging (95 younger; 93 older) and AD spectrum (44 HC; 84 amnestic mild cognitive impairment [aMCI]; 41 AD)-was source-localized using eLORETA to DMN regions. Alpha band (8-13 Hz) MIR and OIR were computed through multivariate spectral analysis. Group differences were tested using t-tests or analysis of covariance (ANCOVA) with multiple comparison correction. Classification (OIR, MIR, demographic, and combined feature sets) used cross-validated logistic-regression, linear-SVM, and random-forest models, with bootstrap 95% confidence intervals and DeLong tests for AUC comparisons.
Results:
OIR and its redundancy component were significantly reduced in older versus younger adults and in AD versus HC/aMCI, with no HC-aMCI differences. The synergy component showed no group differences. MIR decreased broadly with aging and fronto-parietally in AD. Regarding classification (AD spectrum dataset, cross-validated AUC), OIR-based metrics outperformed MIR (AD vs. HC: 0.93 vs. 0.73; AD vs. aMCI: 0.93 vs. 0.71; aMCI vs. HC: 0.48 vs. 0.46). Combining demographics with all information-theoretic features improved AD vs. HC (0.98; DeLong p = 0.023) but not AD vs. aMCI (0.93), where OIR alone was already at ceiling; no feature set exceeded chance for aMCI vs. HC. After correction, OIR and its redundancy component correlated positively with MoCA scores; MIR and the synergy component did not.
Conclusions:
Alpha-band three-order DMN interactions-particularly redundant information processing-decline with aging and AD and provide additional information beyond two-order connectivity for diagnostic classification. OIR offers complementary measures to traditional metrics, and future studies should examine its value when combined with more established AD biomarkers.
