Liquid State Machines and Large Simulations of Mammalian

Liquid State Machines and Large Simulations of Mammalian Visual System Grzegorz M. Wójcik 14 XII 2004

Introduction • • Neuron Brain Visual System and Visual Cortex Hodgkin-Huxley Model Liquid State Machine Self Organizing Criticality Results and plans for the future

Neuron • Soma, axon, synapses, dendrites • Role of ion channels

The Brain

Visual System and Visual Cortex

Hodgkin-Huxley Model • Neuron – Set of electric circuits

LSM • LSM – Liquid State Machine (Maass, 2002)

Typical model of VS

Our Model of Visual System „Eye” (Retina) 100 HH neurons „Liquid” 25 × HHLSM 600 HH neurons „Readout” 100 – 2500 HH neurons

SOC Phenomena • SOC – Self Organizing Criticality • Lots of complex systems in the Universe behave following the exponential law: • We have analyzed the work of different readouts from 10 x 10 to 51 x 51 neurons

Readout Structure (PVC) N 20, 20 N 20, 21 N 20, 22 N 20, 23 N 20, 24 N 20, 25 N 20, 26 N 20, 27 N 20, 28 N 20, 29 N 20, 30 N 21, 22 N 21, 23 N 21, 24 N 21, 25 N 21, 26 N 21, 27 N 21, 28 N 21, 29 N 21, 30 N 22, 21 N 22, 22 N 22, 23 N 22, 24 N 22, 25 N 22, 26 N 22, 27 N 22, 28 N 22, 29 N 22, 30 N 23, 21 N 23, 22 N 23, 23 N 23, 24 N 23, 25 N 23, 26 N 23, 27 N 23, 28 N 23, 29 N 23, 30 N 24, 21 N 24, 22 N 24, 23 N 24, 24 N 24, 25 N 24, 26 N 24, 27 N 24, 28 N 24, 29 N 24, 30 N 25, 21 N 25, 22 N 25, 23 N 25, 24 N 25, 25 N 25, 26 N 25, 27 N 25, 28 N 25, 29 N 25, 30 N 26, 21 N 26, 22 N 26, 23 N 26, 24 N 26, 25 N 26, 26 N 26, 27 N 26, 28 N 26, 29 N 26, 30 N 27, 21 N 27, 22 N 27, 23 N 27, 24 N 27, 25 N 27, 26 N 27, 27 N 27, 28 N 27, 29 N 27, 30 N 28, 21 N 28, 22 N 28, 23 N 28, 24 N 28, 25 N 28, 26 N 28, 27 N 28, 28 N 28, 29 N 28, 30 N 29, 21 N 29, 22 N 29, 23 N 29, 24 N 29, 25 N 29, 26 N 29, 27 N 29, 28 N 29, 29 N 29, 30 N 30, 21 N 30, 22 N 30, 23 N 30, 24 N 30, 25 N 30, 26 N 30, 27 N 30, 28 N 30, 29 N 30, 30

Avalanches of Spike Potentials

Avalanches of Spike Potentials

Time of Simulation (1 processor)

Time of Simulation (1 processor) 33 x 33

Time of Simulation (6 processors) 51 x 51

Summary • In the model of primary visual cortex some SOC phenomena occur • They may be connected i. e. with visual consciousness • Parallelization dramatically shortens the time of simulation

Future Plans • We are creating more sophisticated model of the mammalian visual system • We will continue on the investigation of SOC phenomena • Parallel version of GENESIS (for the MPI environment) will then be applied • As a part of CLUSTERIX model we will simulate large biological neural networks consisting up to half million artificial cells • This will help us to understand some processes occurring in the brain • GRID tests for numerical solving of nonlinear differential equations will be conducted as well

THE END