Kinetics of NREM delta EEG power density across NREM periods depend on age and on delta-band designation.

Study Objectives: (1) To determine whether children and elderly exhibit the atypical kinetics of very low frequency (VLF) power found in young adults, (2) to test the hypothesis that variations in "delta" bandwidth designations can explain discrepancies in whether normalized delta power density declines across non-rapid eye movement periods (NREMPs) linearly or shows the curvature expected of exponential change, and (3) to test our hypothesis that the decline in normailized delta power density in children across NREMPs would have a slope similar to that which we had previously found in young adults and elderly.

Methods: In 3 age groups (mean ages 11, 22, and 71 years) NREM electroencephalograms were analyzed with fast Fourier transform for frequencies between 0.3 and 4 Hz in bands.