The way of explaining this by saying that the brain does everything is new explanation. Because you can hear smell, think, talk. And you have no other way of explaining how... There's a battle there must be gold. Yes. Step back a little from the world. Now you have to take two steps back. Earlier people had to step back from the material world. You have to step back into the virtual world and from the materialworld into ... yes.
Swami Sarvapriyananda teaches one of the shortest and most profound upanishads accompanied by Gaudapada's Karika. This lecture covers Mantra 7 (Part 2).