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It is now recognized that extensive maturational changes take place in the human brain during adolescence, and that the trajectories of these changes are best studied longitudinally. We report the first longitudinal study of the adolescent decline in non-rapid eye movement (NREM) delta (1-4 Hz) and theta (4-8 Hz) EEG. Delta and theta are the homeostatic(More)
Converging evidence indicates that a profound reorganization of human brain function takes place during adolescence: the amount of deep sleep and the rate of brain metabolism fall sharply; the latency of certain event-related potentials declines; the capacity to recover function after brain injury diminishes; and adult problem-solving "power" appears. A(More)
Many motor commands in the nervous system are associated with corollary discharges which alter the excitability in both sensory and motor systems. These discharges may assist in the distinction between self-generated and externally produced movements; they also allow (or represent) monitoring of the motor commands before the effector response has occurred.(More)
We analyzed the available ontogenetic data (birth to 30 years of age) for: amplitude of delta EEG (DA) waves during sleep; cortical metabolic rate (CMR) measured with positron emission tomography; and synaptic density (SD) in frontal cortex. Each is at the adult level at birth, increases to about twice this level by 3 years of age, and then gradually falls(More)
Delta (1-4 Hz) EEG power in non-rapid eye movement (NREM) sleep declines massively during adolescence. This observation stimulated the hypothesis that during adolescence the human brain undergoes an extensive reorganization driven by synaptic elimination. The parallel declines in synaptic density, delta wave amplitude and cortical metabolic rate during(More)
Sleep EEG in the sigma and delta frequency bands was subjected to spectral analysis in 8 normal young adults. In each subject, power density of sigma and delta oscillated reciprocally during NREM sleep, confirming an observation made initially with period/amplitude analysis. In REM sleep, power density for both frequency bands was at its lowest levels.(More)
Visual measurements of sleep spindles were carried out in 48 elderly and 20 young normal adults. Computed tomography brain scans and psychometric testing were also performed. Earlier findings of reduced spindle abundance, amplitude and duration in the elderly were confirmed. In addition, we demonstrated a linear increase in spindle density and duration(More)
One night's sleep loss in young adults increased delta (0.3-3 Hz) EEG only in the first non-REM period of recovery sleep. The delta increase was limited to frequencies 0.3-4 Hz; within this range, the effects on wave form periods and amplitudes differed by frequency band. These results illustrate the value of computer analysis applied to the physiological(More)