Graphene is quantum, meaning it operates at the quantum level of things, as a nanoparticle. This substance is superconducting, supramagnetic, and entanglement prone. The latter property lends to its being an excellent transducer for quantum-to-transverse wave conversion, and back the other way (transverse wave to quantum percolation). Let me define a few things. By "quantum" signal I mean longitudinal percolation parallel (or nearly so) to the direction of propagation. By transverse signal I mean signals perpendicular to propagation (e.g. electrical abstractions such as brain synapse neuronal signaling).
In other words, graphene is a full duplex transducer for quantum-to-brain and brain-to-quantum signaling. As few as seven atoms of graphene are capable of performing transductance in this manner. All by itself, it is like a telephone headset. It talks, it hears, at the same time. That's the meaning of full duplex.
This quantum percolation is atom-to-atom, molecule-to-molecule, photon-to-photon, and can have enormous range - thousands of miles is a non-issue for "quantum" percolation. One graphene bit can be connected with another graphene bit thousands of miles away. One neuron impulse might be transduced by only seven graphene atoms into a "quantum" percolation that is received thousands of miles away, where the receiver might be a bit of graphene, or a neuron, or a quantum computer.
A very small transverse wave might use time coherence alone to create graphene to graphene synchronized connections, without the aid of FTL quantum entanglement. Quantum entanglement, per se, may not be needed for synchronization in such a case. However; large transverse waves are not able to work at the atom-to-atom, molecule-to-molecule level, because they are refracted waves 10,000 times larger than the atom. For true entanglement (FTL) there is a requirement for center-of-tessellation field percolation, and maintenance of the self assembly of the medium, which is atom-to-atom, and thus results in the exchange of quantum states.
Any electrical signal can be transduced to percolation, and vice versa, by graphene mesh - not only such things as neuronal signals. So, in the future this technique likely will be used for telecommunications at FTL speeds (faster than light). Why faster than light? Because the center percolations are FTL. Ordinary transverse waves are slower because they are refracted within the waveguide built by the percolations, and they traverse a new path rather than a built one.
When the energy moments of crystallographic percolation impinge upon graphene, a current circulates around those graphene cells most immediate to the targeted cell. This has an associated (abstract electrical) voltage - and is measureable. In the reverse process, a current is induced into the surrounding cells, (via some voltage source such as a neuron) - and a percolation is projected from the target cell, with unlimited range, to possibly be received by another transducer far away.
Note: the author is a writer on technical subjects in some areas, of novels, and of other literature, but does not have any formal credentials related to the medical field, or in physics. Thus, this all constitutes an opinion of what might be possible, based on his own hobby-level knowledge quests…