Global EEG coherence as a marker for cognition in older adults at risk for dementia

Abstract

Quantitative electroencephalography (EEG) provides useful information about neurophysiological health of the aging brain. Current studies investigating EEG coherence and power for specific brain areas and frequency bands have yielded inconsistent results. This study assessed EEG coherence and power indices at rest measured over the whole skull and for a wide frequency range as global EEG markers for cognition in a sample at risk for dementia. Since global markers are more reliable and less error‐prone than region‐ and frequency‐specific indices they might help to overcome previous inconsistencies. Global EEG coherence (1–30 Hz) and an EEG slowing score were assessed. The EEG slowing score was calculated by low‐frequency power (1–8 Hz) divided by high‐frequency power (9–30 Hz). In addition, the prognostic value of the two EEG indices for cognition and cognitive decline was assessed in a 5‐year follow‐up pilot study. Baseline global coherence correlated positively with cognition at baseline, but not with cognitive decline or with cognition at the 5‐year follow‐up. The EEG slowing ratio showed no significant association, neither with cognition at baseline or follow‐up, nor with cognitive decline over a period of 5 years. The results indicate that the resting state global EEG coherence might be a useful and easy to assess electrophysiological correlate for neurocognitive health in older adults at risk for dementia. Because of the small statistical power for the follow‐up analyses, the prognostic value of global coherence could not be determined in the present study. Future studies should assess its prognostic value with larger sample sizes.

Does the MRI/fMRI Procedure Itself Confound the Results of Meditation Research? An Evaluation of Subjective and Neurophysiological Measures of TM Practitioners in a Simulated MRI Environment

“…This disparity in ages is a factor that could have affected some of the differences seen between these two groups. Notably, global coherence (1-30 Hz) is reported to decrease with age, along with a slowing of peak frequency (ratio of 1-8 Hz power/9-30 Hz power (Laptinskaya et al, 2019). However, this general age effect cannot easily explain the results we reported in this study.…”

Neural Kinesthetic Contribution to Motor Imagery of Body Parts: Tongue, Hands, and Feet

“…The cortical network across the sources, i.e., global EEG coherence across all frequency bands (1–45 Hz), a functional connectivity analysis was performed by applying the coherence method (Rosenberg et al, 1989 ; Laptinskaya et al, 2020 ) followed by complex demodulation with time and frequency sampling 0.5 Hz, 100 ms in BESA Connectivity 1.0 software (BESA ® ). The number of signal sources for the connectivity analysis was selected as 10, and the locations of dipole orientations in the brain were calculated using the genetic algorithm.…”

Screening Tools and Assessment Methods of Cognitive Decline Associated With Age-Related Hearing Loss: A Review

“…The analysis of EEG spectral power in patients with ARHL may be a potential strategy to reveal meaningful cognition-related results. Furthermore, in addition to the EEG power of each frequency band, other characteristics of the frequency bands can also be used as the basis for cognitive evaluation, such as total power, the linear combination of power values in a specific frequency band, average power, and root mean square power (Moretti et al, 2007 ; Price et al, 2019 ; Seleznov et al, 2019 ; Laptinskaya et al, 2020 ).…”