[tsimionescu]

> Even if the electrical signals that are measured are only echos of the triggering signal, it can be utilised as a control signal.

I'm not thinking of something like echos, but more of auxiliary signals - e.g. Perhaps they are signals to increase energy supply to a particular are of the brain, or for controlling 'peripherals', while the main computation happens in other channels.

It's also an interesting question to see whether the analysis techniques could work on a simpler and clearer machine, one where we know for sure that is controlled only by electrical signals - could we infer what a CPU is doing by just measuring electric currents in various areas, without any knowledge of the code running there? This is an experiment that is eminently doable, especially if we design a core specifically for this purpose (making a large and slow core in order to focus purely on the problem of analysis, not difficulties in probing and data collection).