Slide 1

Stochastic Dynamics as a Principle of Brain Functions: Binary and Multiple Decision and Detection G. Deco, R. Romo and E. Rolls Universitat Pompeu Fabra/ICREA Barcelona UniversidadAutonoma de Mexico Mexico University of Oxford Oxford Slide 2 Neural Mechanisms Underlying Probabilistic Behavior Single Cell Recordings in Awake Monkeys I.Decision-Making: Binary: Vibrotactile Discrimination Task Multiple: Moving Dots Discrimination I.Perceptual Detection: Detection of a Mechanical Vibration Romo et al. Slide 3 Vibrotactile frequency discrimination After Romo and Salinas (2003) Nature Reviews Neuroscience Slide 4 r(t)=a1(t).f1+a2(t).f2+c(t) Response of S1, S2, PFC, MPC Neurons Slide 5 Response of VPC Neurons r(t)=a1(t).f1+a2(t).f2+c(t) Romo, Hernandez and Zainos (2004) Neuron Slide 6 Spiking network for probabilistic decision-making P P P GABA P AMPA NMDA Background... Selective Input I Selective Input II Non-selective Spiking Neuron -> Integrate-and-Fire Model: Spikes Reset EPSP, IPSP Spike Synapses Synaptic Dynamics: Populations of Neurons Slide 7 f1>f2 f1 Attractors Design: Mean-Field Reduction f1>f2 f1 Neurodynamical Mechanisms Bifurcation Diagram Stationary States (Attractors) Choice f1>f2 f1>f2 f1f2 f1 Neurodynamical Mechanisms Attractors Picture S 11 22 22 11 A2 A1 S Phase Space f1>f2 f1f2 f1 Neurodynamical Mechanisms: Flow Diagram Rate Pool f1>f2 Rate Pool f1