My late father-in-law, William C. Schieve, was a physicist with an interest in non-linear systems of all kinds.
In 1991, he published a paper, with PK Das and Z. Zheng called "Chaos in an effective four-neuron neural network," in Physics Letters A. 161: 60-66.
DOI: 10.1016/0375-9601(91)90545-J The abstract to the article reads "A four-effective-neutron system was constructed and its dynamics analyzed. Chaotic behavior and strange attractors were observed. Lyapunov spectra are presented for these attractors." Although I didn't have access to the article, using Michael Hetrick's realization of the NonLinear Circuits "Neuron" module, I set up a four-neuron chaotic feedback circuit in VCV Rack. As you'll hear, occasionally the circuit does settle into repeating patterns - these might or might not correspond to the strange attractors mentioned in the abstract. Nonetheless, the four-neuron gadget does generate interesting patterns, both as controls for a canonic just-intonation set of three oscillators, and as a sound source in its own right. I set up a nice set of controllers on the Korg nanoKey, and improvisationally performed the piece you hear here. Many thanks to David Dunn for first alerting me to the existence of the NonLinear circuits modules, and to Michael Hetrick for suggesting additions to the four-neuron feedback patch to make it even more chaotic. This piece is a follow up to my Caudal Variations, which was also dedicated to Bill's memory, although the mathematics in this piece might be closer to that described in Bill's paper than in the previous work.