Amortized Inference of Neuron Parameters on Analog Neuromorphic Hardware
Summary
This work introduces a non-sequential simulation-based inference (SBI) algorithm to create an amortized neural density estimator (NDE) for approximating the posterior distribution of seven parameters of the adaptive exponential integrate-and-fire (AdEx) neuron model on the analog neuromorphic BrainScaleS-2 (BSS-2) substrate. The researchers constrained the extensive parameter space by training a binary classifier to identify parameter combinations that produce moderate spike counts (1-70 kHz), increasing relevant samples from 2% to 38%. They compared two NDEs: one using handcrafted summary statistics and another incorporating a summary network trained jointly with the NDE. The summary network approach yielded a more focused posterior distribution and generated posterior predictive traces that more accurately captured membrane potential dynamics, whereas handcrafted statistics showed deviations in exact dynamics despite matching included features. The results validate amortized SBI for parameterizing analog neuron circuits, despite observed biases and miscalibration in posteriors.
Key takeaway
For research scientists working with neuromorphic hardware or complex biological models, this study demonstrates that amortized simulation-based inference (SBI) can efficiently parameterize analog neuron circuits. You should prioritize integrating summary networks over handcrafted summary statistics when training neural density estimators (NDEs) to achieve more accurate membrane potential dynamics and focused posterior distributions, especially when dealing with high-dimensional observation data. This approach can significantly reduce the effort in identifying suitable model parameters.
Key insights
Amortized SBI effectively parameterizes analog neuron circuits on neuromorphic hardware, with summary networks outperforming handcrafted statistics.
Principles
- Constrain large parameter spaces to focus inference on regimes of interest.
- Neural density estimators can approximate complex posterior distributions.
- Summary networks improve posterior focus and dynamic accuracy over handcrafted features.
Method
A non-sequential SBI algorithm, BayesFlow, was used to train an amortized NDE. A binary classifier pre-filtered parameter space for moderate spike counts. Two NDEs were compared: one with handcrafted summary statistics and another with a jointly trained summary network.
In practice
- Use binary classifiers to pre-filter large parameter spaces for relevant behaviors.
- Consider summary networks for improved accuracy in membrane potential dynamics.
- Apply amortized SBI to parameterize stochastic analog neuron circuits.
Topics
- Amortized Inference
- Neuromorphic Hardware
- Simulation-Based Inference
- Neural Density Estimators
- AdEx Neuron Model
Best for: Research Scientist, AI Researcher, AI Scientist, Machine Learning Engineer
Related on AIssential
Editorial summary, takeaway, and curation by AIssential. Original article published by cs.NE updates on arXiv.org.