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Better documentation of hh_cond_exp_traub and Brette-2007-compatible refractory time #944
When fixing #473 to make t_ref configurable in hh_cond_exp_traub, we configured the model with
See #329 (comment) for a thorough discussion.
I have mixed feelings about this:
- on the one hand the current behaviour is wrong and the fix is quite obviously better
- on the other hand this feels horribly ad hoc and I feel we should rather try to improve the "spike detection" mechanism.
That being said, I am aware of the fact that it is very likely none of us has the time (nor probably any desire) to do this...
So unless we decide to remove the model altogether, I'll approve the PR ^^"
@Silmathoron This neuron model is used for the "hh_coba" benchmark in the Brette et al (2007) simulator review, so we ought to keep it in NEST. Unfortunately, the paper text does not describe spike or reset mechanisms at all. Benchmark code for different simulators is available on ModelDB, although it is not easy to infer how spike detection is done by the different simulators. The most transparent is Brian:
P=NeuronGroup(4000,model=eqs, threshold=EmpiricalThreshold(threshold=-20*mV,refractory=3*ms), implicit=True,freeze=True,compile=False)
I.e., a fixed threshold at -20 mV and an absolute refractory period of 3 ms. Since no reset is specified, I assume that without the refractory period, Brian would emit spikes for each time step until membrane potential drops below -20 mV.
I have not been able to find threshold conditions for other simulators, although for Neuron this piece of code
looks like there may be a spike threshold of 10 mV.
Quite a mess, but maybe compatibility with the Brian implementation would not be a bad idea?