[hour_glass]

The TMS product they are using to stimulate the receivers brain is pretty interesting.

https://www.magstim.com/products/

I'm pretty skeptical that you could use magnetism to transfer any sort of useful information into someone's brain. I'm guessing it just gives a sensation, or maybe some vague visual effect since it is used on the occipital lobe in this experiment.

[ckemere]

TMS relies on Faraday's Law - a large transient magnetic field induces electrical currents in the brain. When these currents are large enough, they perturb the activity of neurons nearby. (Neurons communicate based on pulses of dynamics in the electrical potential across their cell membranes.) There are also second order effects related to the alignment of the neural structure to the induced field lines, etc.

TMS of motor cortex can induce finger twitches and TMS of visual cortex can induce phosphenes or other visual disturbances. Single TMS pulses have effects that wear off very rapidly, but repetitive TMS may be able to induce therapeutic plasticity (it has been reported to potentially induce seizures - following the normal law that nothing medically useful has no side effects).

[amelius]

Question: assume you have a closed hull around some domain D, and record the electric and magnetic fields E and H at the entire hull; at a later moment you prescribe E and H at the hull; will this setup regenerate the original values of E and H inside the domain D?

[ckemere]

To maybe short-circuit your idea, magneto-encephalography (MEG) uses magnetic field sensors to sense brain activity. Coherent currents from ~100K neurons produce femto-tesla signals (about 1 billionth of the earth's magnetic field). This currently requires liquid helium cooled superconductors (though there is some work trying on nanofabricated room-temperature ultraprecise field sensors). To induce effects, the TMS magnets produce reasonable fractions of a Tesla.