A theoretical technique devised by Bruce Maddox by which the whole of an android's neural net could be rebuilt from a single positronic neuron, used to create Dahj and Soji.
Fractal neuronic cloning rests on the idea that each positronic neuron of a Soong-type android holds the pattern of the whole mind, so that one surviving neuron would be enough to grow a new, complete neural net.
The concept is explained in the Star Trek: Picard premiere Remembrance. At the Daystrom Institute, Agnes Jurati tells Picard that Maddox believed it could be done with a neuron from Data, and that androids produced this way would be made in pairs. Picard realises that the dead Dahj must have a twin.
Maddox, working in hiding with Altan Soong on Coppelius, did succeed, producing synthetic beings of flesh and blood whose minds descend from Data's.