Spatio-Temporal Phase Dynamics of Brain Waves
Project/Area Number |
04650381
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
計測・制御工学
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Research Institution | KYUSHU UNIVBERSITY |
Principal Investigator |
HIRAKAWA Kazuyoshi Kyushu University, Engineering, Professor, 工学部, 教授 (40037718)
|
Project Period (FY) |
1992 – 1993
|
Project Status |
Completed (Fiscal Year 1993)
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Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,600,000 (Direct Cost: ¥1,600,000)
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Keywords | Phase / Brain Wave / Spatio-temporal Dynamics / Intermittent Chaos / Alpha Rhythm / Nonlinearity / Schizophrenia / Fractal Dimension / 非線形ダイナミクス / 精神疾患 / 振動子系 / カオス |
Research Abstract |
Spatio-temporal dynamics of phase and amplitude of brain waves ( alpha, theta and delta rhythms ) has been studied extensively using the complex demodulation method, Lorenz plot, FFT power spectral and fractal dimensional analyzes. Results are summmarized below. 1. Phases of the alpha rhythms of healthy subjects dynamically and complicatedly vary in both time and space ; alpha rhythm is never stable. 2. Under repetitive photic stimuli, the alpha rhythms are entrained in less than one second via the phase-initializing and phase-lockng processes. 3. In the entrainment, the alpha rhythms show the characteristics of the intermittent chaos ; the phase-locking does not continue for more than one second, but bursts aperiodically. 4. As the results of the fractal dimensional analysis, the alpha rhythm is considered to be a dynamical system with high degrees (higher than three at least) of freedom. 5. Spaio-temporal changes of phases and amplitudes of the alopha rhythms of schizophrenics are remarkably less than those of the healthy subjects.
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Report
(3 results)
Research Products
(19 results)