Paul L. Nunez, Brett M. Wingeier, and Richard B. Silberstein; 2001
Abstract: A theoretical framework supporting experimental measures of dynamic properties of human
EEG is proposed with emphasis on distinct alpha rhythms. Robust relationships between measured
dynamics and cognitive or behavioral conditions are reviewed, and proposed physiological bases for EEG
at cellular levels are considered. Classical EEG data are interpreted in the context of a conceptual
framework that distinguishes between locally and globally dominated dynamic processes, as estimated
with coherence or other measures of phase synchronization. Macroscopic (scalp) potentials generated by
cortical current sources are described at three spatial scales, taking advantage of the columnar structure
of neocortex. NewEEG data demonstrate that both globally coherent and locally dominated behavior can
occur within the alpha band, depending on narrowband frequency, spatial measurement scale, and brain
state. Quasi-stable alpha phase structures consistent with global standing waves are observed. At the
same time, alpha and theta phase locking between cortical regions during mental calculations is demonstrated,consistent with neural network formation. The brain-binding problemis considered in the context of EEG dynamic behavior that generally exhibits both of these local and global aspects. But specific
experimental designs and data analysis methods may severely bias physiological interpretations in either
local or global directions.
Xanya Sofra Weiss
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