• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.21-34
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• 2019

This study was an examination of the relevance and clinical significance of electroencephalographic (EEG) indexes (e.g., mental/physical stress and attention) and indexes of heart rate variability (HRV) with regard to cognitive function and physiological health conditions in elderly people. A device was used to record two-channel EEGs of the frontal lobe and a one-channel ECG simultaneously. Subjects were 76 people average aged 73. The significant findings are as follows: First, subjects whose intrinsic alpha rhythm had high amplitude, regardless of peak, showed higher resistance to mental stress and lower physical stress than did subjects with low-amplitutde intrinsic alpha rhythm. Second, HRV, SDNN, and RMSSD indexes showed strong positive correlations between the two groups of subjects regardless of the division of groups. Third, the alpha asymmetry of the left and right sides of the brain in subjects with low-amplitude intrinsic alpha rhythm was larger, and the delta/alpha ratio (reflecting physical stress) and theta/sensorimotor rhythm (SMR) ratio (showing the decline in attention) were bigger. Fourth, the subjects in whom intrinsic alpha rhythm peak occurred during slow rhythm had a higher theta/SMR ratio than did subjects whose peak occurred during fast rhythm, which was related to a steeper decline in attention. Therefore, the presence or absence of intrinsic alpha rhythm peak and amplitude on quantitative EEG may be an index reflecting the cognitive function and physiological health of elderly people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.124-132
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• 2020

This study examines the clinical availability of alpha amplitude, asymmetry and mean frequency in old age as EEG indexes reflecting brain health condition. The EEGs of prefrontal lobes in eye closure state were measured for 4 minutes with 72 male and female elderly people aged 73. Subjects were divided into higher and lower groups based on average values of alpha amplitude, asymmetry and mean frequency. The results of correlations and t-test among EEG indexes were as follows. First, the higher Alpha altitude was, the higher physical and mental stress resistance and left-to-right brain communication were, and the lower mean Alpha mean frequency location was. The higher Alpha asymmetry was, the lower left-to-right communication level was. Second, as Alpha power of right brain was higher than that of left brain, Alpha amplitude and mental stress resistance and left-to-right brain communication level were higher. Third, as Alpha mean frequency location was higher, Alpha amplitude and mental anti-stress level were lowered and arousal level was enhanced. These high correlations and complementary meaning among quantitative EEG indicators demonstrated the possibility of biomarkers reflecting brain health state in old age.