Neural Action Potential Simulator
NAPS is a general tool designed to provide realistic multi-unit-like signals (spikes and EEG). These signals have known properties (e.g. spike times, frequency content) and can be used to test and debug any spike-cutting and clustering algorhithm. NAPS is also designed to generate the corresponding voltage waveforms that can be used (with the proper interfacing harware) to drive any multi-unit data acquisition hardware system (e.g. Neuralynx or Plexon). NAPS can also be used for educational purposes to generate surrogate datasets to test various data analyses routines and functions.
NAPS consists of 2 independent components:
NapsIn.exe lets the user design neuron waveforms of specific shapes, and EEG channels of up to two frequency components each. Neurons can be grouped and merged onto assigned output channels, simulating multi-unit activity. NapsIn generates text files.
NapsOut.exe takes the spike waveforms and EEG designs of NapsIn and generates multi-channels, multi-units waveforms simulating what would be recorded from a electrode array in vivo. All spike times are saved in a text file, so that spike sorting algorithms can be rigorously tested. The output is continuously generated onto any National Instrument output board (with enough output channels), or into a text file.
<Download NAPS 1.0> Beta version.
At this point, we are distributing a compiled version of the code for Windows. To run the compiled version, you do not need the full labview environment, but you will just need the LabView run-time engine (free).
The zip-file comes with one set of example files that contains 5 simulated neurons recorded on 2 single electrodes (sample-5nrns-2chans-1eeg). A brief user manual is included.
We welcome your comments and suggestions.
Channel 1: neuron 0(10 Hz), neuron1(no AHP, 10Hz), neuron2 (very small amplitide, 5Hz)
Channel 2: neuron3(simulated interneuron, symmetric waveform, 30Hz), neuron4(symmetric waveform, wide spikes, 10Hz)
1 EEG channel: mixture of theta (5Hz) and gamma (40Hz) oscillations.
NapsIn Screen Shot:
NapsOut Screen Shot:
Credits: Chris Muller, Sevan Abashian and Jean-Marc Fellous .