EEG Frequency Characteristics in Healthy Advanced Elderly

Changes in electroencephalographic (EEG) activity over the course of the normal aging process demonstrate that elderly individuals exhibit an increase in slow wave activity. In this study, we reexamined findings that EEG activity in healthy elderly individuals aged over 85 years (range 85-94) was the same or different compared to individuals younger than 84 years (range 65-84). We performed EEG frequency analysis to investigate the characteristics of resting state frequency components in a cross-sectional study. In individuals aged 85 and older, the dominant frequency component demonstrated a significant shift toward the slower alpha frequency in the left temporal and occipital regions. However, among the oldest individuals, a spectral peak appeared at 9.0-10.0 Hz, and power curves at peak frequency exhibited a sharp rise. Interestingly, healthy individuals older than 85 did not exhibit an appreciable change in EEG, suggesting that "slowing" is not a characteristic sign of aging.