Laboratory for Social and Neural Systems Research (SNS Lab) Page 1 Nonlinear Oscillations Seminar talk based on Chapter 8 of the book “Spikes, Decisions, and Actions” by Hugh R. Wilson April 13, 2011 Christoph Mathys
Outline April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 2 –The point of nonlinearity –Oscillations and limit cycles –N – S = 1 in the plane (Poincaré) –Poincaré-Bendixson –Wilson-Cowan network oscillator –FitzHugh-Nagumo equations –Hopf bifurcations –Van der Pol equation –Delayed negative feedback –Adaptation and perceptual reversals
The point of nonlinearity April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 3 –In linear systems, there are infinitely many periodic solutions within any sufficiently small neighborhood of a given oscillation. –Nonlinear systems, however, can generate isolated oscillations that are surrounded by open, non-oscillatory trajectories that either spiral toward or away from the oscillation. –Therefore, nonlinear systems capture biological reality better.
Oscillations and limit cycles April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 4
Oscillations and limit cycles April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 5
N – S = 1 in the plane (Poincaré) April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 6
N – S = 1 in the plane (Poincaré) April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 7
Poincaré-Bendixson April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 8
Poincaré-Bendixson April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 9
Wilson-Cowan network oscillator April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 10
Wilson-Cowan network oscillator April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 11
FitzHugh-Nagumo equations April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 12
Hopf bifurcations April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 13
Hopf bifurcations April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 14
Van der Pol equation (heart rhythm) April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 15
Van der Pol equation (heart rhythm) April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 16
Delayed negative feedback April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 17
Adaptation and perceptual reversals April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 18
Adaptation and perceptual reversals April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 19
Adaptation and perceptual reversals April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 20
Adaptation and perceptual reversals April 13, 2011Spikes, Decisions and Actions - Nonlinear Oscillations (Chapter 8) Christoph MathysPage 21