http://pnl.bwh.harvard.edu/pub/pdfs/mccarley_1991SchizRes.pdf

Event-related potentials in schizophrenia: their biological and clinical correlates and new model of schizophrenic pathophysiology

Altered topography of EEG spectral content in schizophrenia.

P300 in schizophrenia: Confirmation and statistical validation of temporal region deficit in P300 topography☆

Mechanisms of EEG generation - historical and actual aspects, Heinz Caspers the EEG - a cryptogram, Hellmuth Petsche generation of cortical field potentials, E.-J. Speckmann and U. Altrup propagation of electrical activity - nonlinear associations and time delays between EEG signals, Jan Pieter Pijn and Fernando Lopes da Silva tests of a new model for normal and abnormal EEG phenomena, John S. Barlow chaotic EEG dynamics, alpha and gamma rhythms related to brain function, Erol Basar et al glial and neuronal generators of sustained potential shifts associated with electrographic seizures, George G. Somjen is the EEG correlated with the brain metabolism and cerebral blood flow?, Wolfgang Kuschinsky functional anatomy of the thalamus, W. Lierse intracellular studies of thalamic neurons generating sleep delta waves and fast (40 Hz) oscillations during arousal, Mircea Steriade et al relations between the EEG of the cortex, thalamus and periaqueductal gray in patients suffering from epilepsy and pain syndromes, H.G. Wieser and A.M. Siegel the alpha activity of NREM sleep, Wolfgang Scheuler et al.

Basic mechanisms of the EEG

Brain maps were recorded on a patient with a multiple personality disorder (10 alternate personalities). Maps were recorded with eyes open and eyes closed during 2 different sessions, 2 months apart. Maps from each alternate personality were compared to those of the basic personality "S", some maps were similar and some were different, especially with eyes open. Findings that were replicated in the second session showed differences from 4 personalities, especially in theta and beta 2 frequencies on the left temporal and right posterior regions. A rank ordering of the differences in the brain maps of the alternate personalities from S were similar to the rank ordering of the differences in personality characteristics, as judged by the psychiatrist dealing with this patient. Maps from S acting like some of her personalities or from a professional actress portraying the different personalities did not reveal significant differences. Some of these findings are consistent with those in the literature, and the importance of detecting artifact in the raw EEG recording is emphasized.

Brain Mapping in a Case of Multiple Personality

Principal components analysis with Varimax rotation was applied to centro-occipital EEG power spectral density (PSD) and asymmetry variables in order to detect the subsets of intercorrelated variables. Seven orthogonal variable subsets (factors) were found: left and right PSDs from 0 to 8, 6 to 12, 12 to 20, and 12 to 30 Hz, and asymmetries from 0 to 6, 6 to 14, and 14 to 30 Hz. Attempts to validate these results suggest that the factors are satisfactorily orthogonal and account for a large part of the original data variance. The same set of factors appears to be present in normal subjects, stabilized alcoholics, and some chronic schizophrenics. More effective use of multivariate data in later statistical tests may be made possible by replacing the original variables with the factor scores computed from a weighted sum of the variables in the factors. Also, factor extraction allows comparison of the variable organization in different subject groups. This can have both physiological and statistical significance.

E. A. Serafetinides

Papers

Preprocessing by factor analysis of centro-occipital EEG power and asymmetry from three subject groups