Nonlinear Dynamic Analysis Using Lyapunov Exponent of EEG in Patients with Schizophrenia.
- Author:
Dai Jin KIM
1
;
Chi Un PAE
;
Jaeseung JEONG
;
Jeong Ho CHAE
;
Soo Yong KIM
;
Hyo Jin GO
;
In Ho PAIK
Author Information
1. Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Korea.
- Publication Type:Original Article
- Keywords:
Schizophrenia;
Chaos;
EEG;
Nonlinear dynamics;
Lyapunov exponent
- MeSH:
Brain;
Electrodes;
Electroencephalography*;
Head;
Humans;
Nonlinear Dynamics*;
Schizophrenia*
- From:Korean Journal of Psychopharmacology
1998;9(1):67-72
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECT: It seemed worthwhile to estimate nonlinear measures of the electroencephalogram (EEG) in schizophrenic patients, because nonlinear measures might serve as indicators of the specific brain function in schizophrenia. METHOD: Previous studies which estimated the chaoticity in the brain of schizophrenia with nonlinear methods recorded the EEGs at limited electrodes, so we tried to record EEGs from 16 channels for nonlinear analysis in 19 patients with Schizophrenia and 8 healthy control subjects. We employed a new method to calculate the nonlinear invariant measures. For limited noisy data, this algorithm was strikingly faster and more accurate than previous ones. RESULTS: Our results showed that the schizophrenic patients had lower values of the largest positive Lyapunov exponent at the left inferior frontal and anterior temporal head regions compared with normal controls. CONCLUSIONS: These results suggest that the nonlinear analysis of the EEGs such as the estimation of the largest positive Lyapunov exponent seems to be a useful tool in analyzing EEG data to explore the neurodynamics of the brain of schizophrenic patients.
