Transverse relationships of the alpha rhythm on the scalp.

Using auto- and cross-spectral analyses on data of 3 normal adult subjects, two components of rhythmic alpha activity were distinguished with respect to their spatial distribution and spatial relationships on the scalp. Derivations from 21 scalp points vs. linked ears were analyzed. The alpha activity with power maxima in the bilateral occipital areas (component A) showed high coherence with activity in the anterior areas and somewhat lower coherence with activity in the central/parietal areas. The other component (B) appeared dominantly in the central areas, showing extremely low values of coherence between the anterior and posterior regions, and an unstable phase relation among recording points. Components A and B appear to correspond to the 'generalized' and 'localized' alpha components described earlier. It is suggested that these two components account for the major properties of the rhythmic alpha activity.

[1]  E. D. Adrian,et al.  THE ORIGIN OF THE BERGER RHYTHM , 1935 .

[2]  J. Beaumont,et al.  A critical review of EEG coherence studies of hemisphere function. , 1984, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[3]  J G Beaumont,et al.  Asymmetry in EEG alpha coherence and power: effects of task and sex. , 1978, Electroencephalography and clinical neurophysiology.

[4]  R. Cooper,et al.  Spatial and temporal characteristics of the alpha rhythm: a toposcopic analysis. , 1960, Electroencephalography and clinical neurophysiology.

[5]  F. Duffy,et al.  Significance probability mapping: an aid in the topographic analysis of brain electrical activity. , 1981, Electroencephalography and clinical neurophysiology.

[6]  P. Nunez,et al.  Electric fields of the brain , 1981 .

[7]  G C Galbraith,et al.  EEG correlates of visual-motor practice in man. , 1975, Electroencephalography and clinical neurophysiology.

[8]  A. Rémond,et al.  The alpha average. I. Methodology and description. , 1969, Electroencephalography and clinical neurophysiology.

[9]  D. Lehmann Multichannel topography of human alpha EEG fields. , 1971, Electroencephalography and clinical neurophysiology.

[10]  K Shinosaki,et al.  The direction of spread of alpha activity over the scalp. , 1983, Electroencephalography and clinical neurophysiology.

[11]  D Lehmann,et al.  Averaging of spectral power and phase via vector diagram best fits without reference electrode or reference channel. , 1986, Electroencephalography and clinical neurophysiology.

[12]  H. Hori,et al.  A study on phase relationship in human alpha activity. Correlation of different regions. , 1969, Electroencephalography and clinical neurophysiology.

[13]  K Shinosaki,et al.  Spatial distribution of generators of alpha activity. , 1986, Electroencephalography and clinical neurophysiology.

[14]  J. W. Kuhlman,et al.  Functional topography of the human mu rhythm. , 1978, Electroencephalography and clinical neurophysiology.

[15]  G. Wieneke,et al.  Normative spectral data on alpha rhythm in male adults. , 1980, Electroencephalography and clinical neurophysiology.

[16]  H Suzuki,et al.  Phase relationships of alpha rhythm in man. , 1974, The Japanese journal of physiology.

[17]  P. Nunez Wavelike Properties of the Alpha Rhythm , 1974 .

[18]  H. Ozaki,et al.  Developmental characteristics of normal and mentally retarded children's EEGs. , 1981, Electroencephalography and Clinical Neurophysiology.

[19]  W. R. Adey,et al.  Comprehensive spectral analysis of human EEG generators in posterior cerebral regions. , 1966, Electroencephalography and clinical neurophysiology.

[20]  Duilio Giannitrapani,et al.  The Electrophysiology of Intellectual Functions , 1984 .

[21]  G Dumermuth,et al.  Spectral analysis of all-night sleep EEG in healthy adults. , 1983, European neurology.