Brain waves are due to feedback paths and dynamics - oscillations etc, but LLM connectivity is far simpler. In an LLM there is a strict bottom-up one-way flow of information, with no looping. There is no way for a higher up layer to affect a lower down layer, whether directly or indirectly.

But there is no LLM mechanics. You can certainly take measurements along the neural net and show a wave like pattern of activation. But no such wave can be measured in the hardware. An artificial neuron is really doing nothing to produce physical weave behavior that’s measurable.