Circuits.H

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/*!@file ModelNeuron/Circuits.H Class for various types of simple
   neural circuits */

// //////////////////////////////////////////////////////////////////// //
// The iLab Neuromorphic Vision C++ Toolkit - Copyright (C) 2001 by the //
// University of Southern California (USC) and the iLab at USC.         //
// See http://iLab.usc.edu for information about this project.          //
// //////////////////////////////////////////////////////////////////// //
// Major portions of the iLab Neuromorphic Vision Toolkit are protected //
// under the U.S. patent ``Computation of Intrinsic Perceptual Saliency //
// in Visual Environments, and Applications'' by Christof Koch and      //
// Laurent Itti, California Institute of Technology, 2001 (patent       //
// pending; application number 09/912,225 filed July 23, 2001; see      //
// http://pair.uspto.gov/cgi-bin/final/home.pl for current status).     //
// //////////////////////////////////////////////////////////////////// //
// This file is part of the iLab Neuromorphic Vision C++ Toolkit.       //
//                                                                      //
// The iLab Neuromorphic Vision C++ Toolkit is free software; you can   //
// redistribute it and/or modify it under the terms of the GNU General  //
// Public License as published by the Free Software Foundation; either  //
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// The iLab Neuromorphic Vision C++ Toolkit is distributed in the hope  //
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// PURPOSE.  See the GNU General Public License for more details.       //
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// You should have received a copy of the GNU General Public License    //
// along with the iLab Neuromorphic Vision C++ Toolkit; if not, write   //
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// Boston, MA 02111-1307 USA.                                           //
// //////////////////////////////////////////////////////////////////// //
//
// Primary maintainer for this file: David Berg <dberg@usc.edu>
// $HeadURL: svn://ilab.usc.edu:/trunk/saliency/src/ModelNeuron/Circuits.H $

#ifndef MODELNEURON_CIRCUITS_H_DEFINED
#define MODELNEURON_CIRCUITS_H_DEFINED

#include "ModelNeuron/NeuralColumn.H"
#include "ModelNeuron/IZNeuron.H"

// ######################################################################
//! A Threshold circuit that slowly accumulates input and then
//releases a short burst of spikes. The circuit contains a regular
//spiking neuron that will spike tonically when stimulated and
//excite a burst neuron that will integrate its input and produce a
//short burst of spikes when a threshold is reached. The regular
//spiking neuron also feeds to a fast spiking interneuron, which
//inhibits the burst neuron.
//######################################################################
struct ThresholdCircuit : public NeuralColumn<IZNeuron>
{
  ThresholdCircuit(const double& thresh = 1, const std::string& name="Threshold", const std::string& units="Spike")
    : NeuralColumn<IZNeuron>(SimTime::MSECS(1.0), SimUnit::STRICT, name, units)
  {
    addSub(RSNeuron());
    addSub(EBNeuron());
    addSub(FSNeuron());
    
    addWeight(-1, 0, 1.0F);//input->RS
    addWeight(0,  1, thresh * 1.0F);//RS->EB
    addWeight(1, -1, 1.0F);//EB->output
    addWeight(0,  2,  3.0F);//RS->FS
    addWeight(2,  1, -1.0F);//FS->EB
  }
};

// ######################################################################
//! A bandpass filter to demonstrate use of NeuralColumn
//! calculates a bandpass as a lowpass subtract a larger lowpass
//######################################################################
struct BandpassFilter : public NeuralColumn<SimUnit*>
{
  BandpassFilter(const double& tau, const double& bandwidth, const SimTime time, 
                 const std::string& name="Bandpass", const std::string& units="pA") 
    :   NeuralColumn<SimUnit*>(time, SimUnit::NORMAL, name, units)
  {
    double simtime = 1;
    if (tau / 5.0 >= 1.0)
      simtime = tau/5;

    addSub( LowPassMaxRect(tau, 0.0, 0.0, 1.0, SimTime::MSECS(simtime)) );
    addSub( LowPass(tau + tau*bandwidth, 0.0, SimTime::MSECS(simtime)) );
    
    addWeight(-1, 0, 1.0F);
    addWeight(0, 1, 1.0F);
    addWeight(0, -1, 1.0F);
    addWeight(1, -1, -1.0F);
  }
};

// ######################################################################
// Register circuits types
// ######################################################################
namespace 
{
  typedef SimUnit::Factory CircuitFactory;
  typedef SimUnit::Creator CircuitCreator;

  //define creation functions
  struct RegisterCircuits
  {
    RegisterCircuits()
    {
      CircuitFactory::instance().add("ThresholdCircuit", CircuitCreator::make<ThresholdCircuit>(1.0));
      CircuitFactory::instance().add("BandpassFilter", CircuitCreator::make<BandpassFilter>(50.0, 1.0, 
                                                                                            SimTime::MSECS(1.0)));
    }
  };
  static RegisterCircuits registercircuits;
}

#endif
// ######################################################################
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