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Quantitative EEG features of depressive disorders
$151 P23.05 QUANTITATIVE EEG FEATURES O F DEPRESSIVE DISORDERS.
L.S. Prichep, E.R. John and A.L. Lieber (New York, NY, USA) The use of quantitative electroencephalograms (QEEG) in the diagnosis and subgrouping of depressive disorders was investigated. Using Research Diagnostic Criteria (RDC), patients with primary affective disorders were divided into unipolar (n = 21) and bipolar (n = 20) sub-types. Secondary depressives with concurrent medical illness (n = 15) were also included. All patients received a neurometric QEEG in a drug-free state within 72 hours of admission to an evaluation unit. One minute artefact-free, eyes closed EEG was recorded from the 19 leads of the International 10/20 system. Quantitative features, including absolute and relative spectral power, inter-hemispheric asymmetry and coherence were extracted and compared to predicted normative values. Departure from expected values was expressed in terms of probability using z-transformations. Univariate features were combined into multivariate composite measures. Using these univariate and multivariate features in stepwise multivariate discriminant analyses, we were able to discriminate with very high accuracy: 1) 'normal' adults from depressed patients; 2) primary from secondary depressed patients: 3) normal, depressed, alcoholic and dementia patients from each other; and, 4) unipolar from bipolar patients. The significant contribution of measures of coherence and asymmetry to making these discriminations will be discussed, An independent replication (n = 80) of these results presently underway will also be presented.
P23.06 A P S Y C H O P H Y S I O L O G I C A L I N F O R M A T I O N PROCESSING APPROACH TO PSYCHOPATHOLOGY: L O N G I T U D I N A L S T U D I E S O F EEG REACTIVITY.
thought-disturbances before any psychopharmacological treatment, and of drug-free, recovered, former schizophrenics showed distinct differences between these two psychopathological conditions in the functional re-adjustment of the brain to incoming information. The results of a new longitudinal study on EEG reactivity before and during treatment of acute schizophrenics with neuroleptics will be presented, in particular, the relation between drug effects on EEG reactivity and on psychopathology.
P23.07 H E M I S P H E R I C MAJOR PSYCHOSIS.
DIFFERENCES
OF
BEAM
IN
K. Kanou, M. Nakamura, T. Matsuoka and S. Takahashi (Otsu, Japan) Recently, much attention has been paid to the morphological and functional association of the cerebral hemispheres with functional psychosis. We have applied Brain Electrical Activity Mapping (BEAM) to numerous psychotics and investigated the topographical differences between hemispheres. Subjects: 13 bipolar patients, 53 major depressives and 53 schizophrenics diagnosed by using DSMIII, were compared with 35 non-psychiatric patients. Methods: Electrodes were placed at 16 scalp sites and bilateral earlobes according to the 10 20 system and BEAMs were recorded by averaging 15 sequential EEG epochs with an analysis-time of ca.2sec. Results: Alpha bands appeared predominantly at the right parieto-occipital area for schizophrenics (41%) and controls (60%), whereas it predominated over the left hemisphere for bipolar patients (54%) and major depressives (56%). Depressives with 'slow' alpha rhythm showed left parieto-occipital predominance more than those showing 10Hz alpha rhythm. Furthermore. theta rhythm was relatively well distributed over the parieto-occipital area. These results suggest that the right hemisphere may be relatively hyperaroused in depression.
M. Koukkou, B. Woggon and J. Angst (ZiJrich, Switzerland) The main assumption for this approach is that the mode of brain functioning is continuously re-adjusted in answer to the current demands which are made by surround information. The basic psychophysiological mechanism for this re-adjustment is the orienting reaction (OR). The EEG components of the O R are measured as EEG reactivity; this measure permits a physiological assessment of the achieved re-adjustment. In an information processing approach, the EEG components of the O R reflect the initial interpretation of information by the brain (and correspond to the psychological process of allocation of attention), and introduce the brain's functional state during which the subsequent cognitive processing occurs. Differences in cognitive processing in normals are paralleled by differences in EEG reactivity. Our studies of acute schizophrenics with hallucinations and
P23.08 H E M I S P H E R I C A S Y M M E T R Y OF S L O W BRAIN P O T E N T I A L S INDICATES TASK-SPECIFIC PREPARATION.
B. Cevey, T. Elbert, B. Rockstroh, W. Lutzenberger and N. Birbaumer (Ttibingen, W. Germany.) Hemispheric asymmetry of slow brain potenlials (CNV) was investigated prior to and during performance of sensori-motor tasks. Tactile stimuli of 1 sec duration were applied to index and middle fingers of one hand as warning stimulus (WS); 6 sec later a tactile choice reaction time task was presented to the same hand (group SAME) or to the opposite hand (group OPPOSITE). The EEG was recorded (time constant ~ ) from F3, F4, C3, C4, P3, P4 referred to shunted earlobes. A slow
L.S. Prichep, E.R. John and A.L. Lieber (New York, NY, USA) The use of quantitative electroencephalograms (QEEG) in the diagnosis and subgrouping of depressive disorders was investigated. Using Research Diagnostic Criteria (RDC), patients with primary affective disorders were divided into unipolar (n = 21) and bipolar (n = 20) sub-types. Secondary depressives with concurrent medical illness (n = 15) were also included. All patients received a neurometric QEEG in a drug-free state within 72 hours of admission to an evaluation unit. One minute artefact-free, eyes closed EEG was recorded from the 19 leads of the International 10/20 system. Quantitative features, including absolute and relative spectral power, inter-hemispheric asymmetry and coherence were extracted and compared to predicted normative values. Departure from expected values was expressed in terms of probability using z-transformations. Univariate features were combined into multivariate composite measures. Using these univariate and multivariate features in stepwise multivariate discriminant analyses, we were able to discriminate with very high accuracy: 1) 'normal' adults from depressed patients; 2) primary from secondary depressed patients: 3) normal, depressed, alcoholic and dementia patients from each other; and, 4) unipolar from bipolar patients. The significant contribution of measures of coherence and asymmetry to making these discriminations will be discussed, An independent replication (n = 80) of these results presently underway will also be presented.
P23.06 A P S Y C H O P H Y S I O L O G I C A L I N F O R M A T I O N PROCESSING APPROACH TO PSYCHOPATHOLOGY: L O N G I T U D I N A L S T U D I E S O F EEG REACTIVITY.
thought-disturbances before any psychopharmacological treatment, and of drug-free, recovered, former schizophrenics showed distinct differences between these two psychopathological conditions in the functional re-adjustment of the brain to incoming information. The results of a new longitudinal study on EEG reactivity before and during treatment of acute schizophrenics with neuroleptics will be presented, in particular, the relation between drug effects on EEG reactivity and on psychopathology.
P23.07 H E M I S P H E R I C MAJOR PSYCHOSIS.
DIFFERENCES
OF
BEAM
IN
K. Kanou, M. Nakamura, T. Matsuoka and S. Takahashi (Otsu, Japan) Recently, much attention has been paid to the morphological and functional association of the cerebral hemispheres with functional psychosis. We have applied Brain Electrical Activity Mapping (BEAM) to numerous psychotics and investigated the topographical differences between hemispheres. Subjects: 13 bipolar patients, 53 major depressives and 53 schizophrenics diagnosed by using DSMIII, were compared with 35 non-psychiatric patients. Methods: Electrodes were placed at 16 scalp sites and bilateral earlobes according to the 10 20 system and BEAMs were recorded by averaging 15 sequential EEG epochs with an analysis-time of ca.2sec. Results: Alpha bands appeared predominantly at the right parieto-occipital area for schizophrenics (41%) and controls (60%), whereas it predominated over the left hemisphere for bipolar patients (54%) and major depressives (56%). Depressives with 'slow' alpha rhythm showed left parieto-occipital predominance more than those showing 10Hz alpha rhythm. Furthermore. theta rhythm was relatively well distributed over the parieto-occipital area. These results suggest that the right hemisphere may be relatively hyperaroused in depression.
M. Koukkou, B. Woggon and J. Angst (ZiJrich, Switzerland) The main assumption for this approach is that the mode of brain functioning is continuously re-adjusted in answer to the current demands which are made by surround information. The basic psychophysiological mechanism for this re-adjustment is the orienting reaction (OR). The EEG components of the O R are measured as EEG reactivity; this measure permits a physiological assessment of the achieved re-adjustment. In an information processing approach, the EEG components of the O R reflect the initial interpretation of information by the brain (and correspond to the psychological process of allocation of attention), and introduce the brain's functional state during which the subsequent cognitive processing occurs. Differences in cognitive processing in normals are paralleled by differences in EEG reactivity. Our studies of acute schizophrenics with hallucinations and
P23.08 H E M I S P H E R I C A S Y M M E T R Y OF S L O W BRAIN P O T E N T I A L S INDICATES TASK-SPECIFIC PREPARATION.
B. Cevey, T. Elbert, B. Rockstroh, W. Lutzenberger and N. Birbaumer (Ttibingen, W. Germany.) Hemispheric asymmetry of slow brain potenlials (CNV) was investigated prior to and during performance of sensori-motor tasks. Tactile stimuli of 1 sec duration were applied to index and middle fingers of one hand as warning stimulus (WS); 6 sec later a tactile choice reaction time task was presented to the same hand (group SAME) or to the opposite hand (group OPPOSITE). The EEG was recorded (time constant ~ ) from F3, F4, C3, C4, P3, P4 referred to shunted earlobes. A slow