On the existence of different alpha band rhythms in the hand area of man.
Earlier investigations have reported that the Rolandic mu rhythm and the parieto-occipital alpha rhythm, the latter thought to be volume-conducted into central areas, both contribute to scalp-recorded electroencephalogram (EEG) in the central region of humans. The present study applies dynamic cross-spectral analysis to event-related EEG data recorded during finger movement. In 10 of 12 subjects, a superposition of Rolandic mu rhythms and bilaterally coherent alpha band rhythms is found in the central area; however, the use of closely-spaced Laplacian derivations rules out volume-conduction effects, providing evidence that both rhythms are generated in the underlying neocortical circuitry. An explanation for the coexistence of these rhythms in terms of a global/local EEG model is provided.
Andrew
C
C
Ludwig Boltzmann-Institute of Medical Informatics and Neuroinformatics, Austria. andrew@dpmi.tu-graz.ac.at
Pfurtscheller
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G
D000513:Alpha Rhythm / Q000706:statistics & numerical data; D005385:Fingers / Q000502:physiology; D006801:Humans; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*