EEG Coherence Obtained From an Auditory Oddball Task Increases With Age

Abstract

Changes in coherence with aging during cognitive tasks have, until now, not been investigated. However, several fMRI and positron emission tomography studies of cognitive tasks have found increased bilateral activity in elderly subjects. Changes in coherence with aging during a cognitive task were investigated to see if EEG coherence was present in older adults. An auditory oddball task, which is a widely used test for cognitive function, was used. Eleven young adults (27.8 +/- 4.8 years, six females) and 10 older adults (61.3 +/- 4.6 years, six females) were studied, and both interhemispheric and long- and short-range intrahemispheric coherence were considered. Higher interhemispheric coherence was found in the older subjects in the delta band. Short intrahemispheric coherence was also increased in the theta, delta, and alpha bands. Higher coherence, although not significantly different, was also found for all other coherence types and bands, except for long intrahemispheric coherence in the low gamma band. The results presented here provide the first evidence that aging is associated with increased EEG coherence during a relatively easy cognitive task.

Sensitivity of EMG-EMG coherence to detect the common oscillatory drive to hand muscles in young and older adults

“…Although few studies have examined the role of an altered oscillatory drive in healthy older adults (Ͼ65 yr), this finding is consistent with the finding of increased interhemispheric EEG-EEG coherence (Maurits et al 2006;ten Caat et al 2008) and increased EEGand MEG-EMG coherence (Johnson and Shinohara 2012;Kamp et al 2011) in older adults during the performance of neurocognitive and motor tests. Increased oscillatory drive measured with motor unit recordings has also been linked with impaired performance during hand tasks in younger adults Kakuda et al 1999), and older adults frequently perform worse on motor tasks .…”

“…Without a change in the common oscillatory drive that is shared across muscles, there would be no significant change in EMG-EMG coherence with advancing age. Thus increases in EEG-EEG (Maurits et al 2006;ten Caat et al 2008) or EEG-EMG (Johnson and Shinohara 2012) coherence with advancing age do not necessarily indicate that EMG-EMG coherence would correspondingly increase in older adults.…”

High-density EEG coherence analysis using functional units applied to mental fatigue

“…Disjoint segments ([−0.1, 0.88] s around the stimulus) were used for further analysis, consisting of responses for 20 trials at each switch. We used an average reference which is suitable for coherence analysis of high-density EEG (Nunez et al, 1997;Maurits et al, 2006), applied a high-pass filter (0.16 Hz) and a notch filter (50 Hz), and resampled from 500 Hz to 512 Hz (BrainVision Analyzer 1.05, Brain Products GmbH). Then data were transferred to EEGLAB (Delorme and Makeig, 2004), running under Matlab (The MathWorks).…”

“…This usually makes a regular subselection of the available coherences (Maurits et al, 2006), because coherence analysis of all electrode pairs would be cumbersome for highdensity EEG. A major drawback of this approach is that the majority of the coherences is ignored.…”

Data-Driven Visualization and Group Analysis of Multichannel EEG Coherence with Functional Units

“…Synchronous electrical activity in different brain regions is generally assumed to imply functional relationships between these regions. A measure for this synchrony is EEG coherence, calculated between pairs of electrode signals as a function of frequency [1], [2].…”