Does the brain create consciousness? Donald Hoffman says it doesn't

Hoffman says no, and he says the standard answer can't be right. Most consciousness researchers look for neural correlates of consciousness on the assumption that space, time, and physical systems like neurons are fundamental. Hoffman's argument is that if perception isn't showing us reality as it is, then brains and neurons aren't reality as it is either, so they can't be the thing producing experience.

Not in the sense of nothing being there. Hoffman's claim is that something is definitely there and that our perceptions are a format for interacting with it, not a picture of it. He compares it to a virtual reality headset: the headset is real, the game is real enough to play, but the red Ferrari you see isn't sitting inside the supercomputer. He calls the headset useful and cheap, not empty.

He means it the way a computer desktop is an interface. The desktop is useful because it hides the truth of what the machine is doing and lets you control it anyway. If you had to toggle millions of voltages by hand to open a photo, you'd never get anything done. Hoffman says evolution handed us the same kind of shortcut, and that space and time are the format of the headset rather than the world itself.

Because, in Hoffman's telling, evolution isn't scoring you on truth. He and his graduate students Justin Mark and Brian Marion ran evolutionary game theory simulations and found that organisms who saw reality as it is went extinct against organisms tuned only to fitness payoffs. The deeper result surprised him: fitness payoff functions almost never contain information about the structure of the world, so they have nothing to shape your senses toward the truth with.

Hoffman points to physicists rather than to himself here. He cites a 2005 paper by Nobel laureate David Gross that says, in a direct quote, spacetime is doomed and cannot be fundamental, because it has no operational meaning below the Planck scale of ten to the minus thirty-three centimeters and ten to the minus forty-three seconds. Hoffman is careful to say this is the view of high energy theoretical physicists specifically, and that many other physicists haven't even heard of it.

It's his proposal for what sits outside spacetime. He models an enormous, possibly infinite network of conscious agents that have experiences and affect each other's experiences, written down as a Markovian dynamics. He compares it to a social network like Twitter, with too much going on to take in directly, so you need an interface to see what's trending. In that analogy, spacetime is the interface.

They're mathematical objects physicists have found outside spacetime, and Hoffman treats them as a bridge. Their volumes encode particle scattering probabilities, and computations that take hundreds of pages of algebra inside quantum field theory come down to three or four terms with them. The amplituhedron was published in 2014 by Nima Arkani-Hamed and Jaroslav Trnka. Hoffman's Fusions of Consciousness paper maps his conscious agent dynamics onto decorated permutations, which are the combinatorial objects that classify these geometries.

Mostly not, and he says so himself. Hoffman states that about 99 percent of his colleagues disagree with him and continue to assume physical systems are fundamental. He also describes a published philosophical objection, that he's using the math of evolution to undercut evolution's own assumptions. His reply is that every precise theory eventually shows you its own limits, and that finding those limits is how science normally works.

Hoffman says death would be taking off the headset. His reasoning is that consciousness doesn't depend on the headset, the headset depends on consciousness, so destroying the interface doesn't touch the thing wearing it. He pushes it further in the episode, saying he has no neurons right now because they don't exist when they aren't perceived, and that he's therefore conscious without a brain at this moment. He presents this as the implication of his theory, not as a proven fact about dying.

He draws a sharp line between his head and his gut. He says the intellectual argument is clear as day and that he doesn't believe it emotionally, and that if you put a gun to his head he'd be scared. This isn't abstract for him. A COVID-related heart inflammation left him in an arrhythmia for 36 hours at 190 beats per minute, and he texted his wife goodbye. He says his heart is still damaged and the fear is smaller than it was but still there.

He says he's on the fence. He notes the standard neuroscience evidence, where brain activity predicts a button press seconds before the person reports deciding, but says those arguments are less compelling to him because neurons don't exist when they aren't perceived. He also describes a mathematical result he'd found two days before the interview, a trace order on Markovian kernels that lets him assign coherent probabilistic free choices to many small agents and to the larger agent they combine into. He hadn't told his collaborator yet and says the math may not survive.

Nick asks him this directly, with his own 11-year-old in mind. Hoffman's answer is the multiplayer video game. Kids already understand playing with avatars alongside someone in another state or another country, and already understand that the avatar isn't the player. The one twist he'd add is the strange part: it may be that there's one player playing every role in the game.