Resting-state electroencephalographic delta rhythms may reflect global cortical arousal in healthy old seniors and patients with Alzheimer's disease dementia

Extending Başar's theory of event-related EEG oscillations, here we hypothesize that even in quiet wakefulness, transient increases in delta rhythms may enhance global cortical arousal as revealed by the desynchronization of alpha rhythms in normal (Nold) seniors with some derangement in Alzheimer's disease dementia (ADD).