Headless Humans: Does Your Brain Need Your Body? | Unveiled

Headless Humans - Does Your Brain Need Your Body?

The “Brain in a Vat” concept is a genuine, philosophical line of thought. It questions our deepest notions of reality and consciousness by arguing that our experiences could actually be the simulated result of a “mad scientist” with our brains - just our brains - hooked to a computer. But, actually, do we have to go quite so sci-fi to be brain-free?

This is Unveiled and today we’re answering the extraordinary question; does your brain need your body?

The debate over the mind-body problem has raged for centuries. Early on in history, it was ancient philosophers like Parmenides of Elea who said that the mind and body are indiscernible from each other and are part of the same entity, requiring each other to survive. This point of view became known as Monism, and was the belief of most philosophers for centuries. It wasn’t until René Descartes argued for mind-body dualism (in the early 1600s) that the other side of the argument became popular. Descartes argued that the mind and body are actually completely separate entities… with very different natures. And that each could be capable of existing without the other.

Fast forward to today, and both sides still have their supporters. As technology and medical science have progressed, however, we have moved closer to answering the question of if a physical brain can indeed survive without a body.

First, what does a brain fundamentally need to really survive? Despite being by far the most complex organ in our bodies - and by some measures the most complex structure in the universe - the brain is remarkably simple in its conditions for survival. All it really needs to function in most animals is two things - oxygen and glucose. Deprive a brain of oxygen and nerve signals fail, messages go undelivered, and the cells quickly die until the entire system irreparably breaks. The glucose, or sugar, is essentially what our brain uses to generate the energy to properly function. So, on the face of it, it would seem that a brain should be able to exist without a whole body… if these basic requirements are met.

But, unfortunately, there’s no real way to know that for sure. Quite apart from all the ethical considerations at play in any kind of experiment to test it… brains can’t especially communicate when they don’t have their bodies. This means that scientists would struggle to know if a brain really was still alive or conscious as usual (without a body) even if that situation was somehow created. Since medical science isn’t yet advanced enough to reattach brains to spinal cords, nor to fully read the “mind” of a brain beyond vague electrical activity, there are some big gray areas involved.

While it’s difficult to know if a brain can carry on without a body, however, we can check to see if the reverse is true. Do bodies need brains to survive? This is something that’s far easier to study, as it does happen in the natural world. Single celled organisms like bacteria, though remarkably simple, are still able to exist (and live) without a brain. They still have DNA with coded instructions on how to survive, so a brain actually isn’t necessary. There are some larger animals with a similar setup, too, including sponges, which have no brain or nervous tissue of any kind. It can then be said that sponges are 100% body. To some degree, this seems to go against evolution, as most animals have developed brains to improve and adapt… but sponges appear to have done the opposite. They may have instead evolved to lose their brain completely because it simply wasn’t needed. Sponges still eat and breathe, but they essentially rely on the surrounding water to do it for them. They are, then, incredibly efficient.

Possibly the most advanced living things without brains, however, are mushrooms. Again, fungi have no brain of any kind, but they are (by some) still thought to be intelligent and even conscious beings. Different mushrooms have been observed to have a short term memory, at least. It’s been shown, too, that they can make decisions, learn for their own benefit, and generally respond to outside stimuli. Apparently cognitive function, without the cognitive center. Fungi don’t think in the traditional sense, but they do still take in environmental factors, consider them, and grow accordingly. They seem to defy our traditional view of intelligence, then. And there's a growing argument that we should incorporate mushrooms into how we more widely explain consciousness, as well.

So, in theory, brains don’t need bodies, just oxygen and glucose… and, in the real world, bodies don’t always need brains. More broadly, though, it’s clear that the body and brain are by some measures extremely difficult to distinguish between. Bodies are defined as the physical structure of an animal, which obviously includes its organs. And, while brain-less animals do exist, there’s no known body-less animal, so far. So a brain (if it’s there) is always part of a body. Meanwhile, at the other end of the spectrum, there are also some animals that have developed more than one brain to survive… with separate, specialized brains that act independently of one another. An octopus, for example, has nine brains - one acting for each of its arms (complete with its own neurons) and one inside its head. That’s why the arms of an octopus move and behave as if they have a mind of their own… because they actually do. In this case, though, those extra brains do still need the body that houses them.

However, and despite the difficulties previously mentioned, science has now moved towards seemingly keeping brains genuinely alive without the body that once carried them. In 2019, researchers published a study in which they kept pig brains “active” for up to 36 hours… after they had been removed from the pigs’ bodies. By utilizing a system called BrainEx, which mimics the blood flow and nutrient delivery of a body, it was shown that at least some of the basic brain functions were sustained - such as sugar consumption and the production of carbon dioxide. Again though, without the bodies to properly signal what the brains were doing, it’s hard to know whether they really were still alive, in a complete sense.

Nevertheless, this idea of keeping a brain alive artificially via technology has come to be called the Isolated Brain approach. And there are some that do see it as the future. The suggestion is that, theoretically, by building increasingly sophisticated machines which perfectly mimic the environment of an active body, a brain could be made to continue operating. We don’t yet see it in nature, but we could soon see it in industry. As to whether such apparent “advances” could ever be applied to human brains, at the moment it’s doubtful. At present, we can’t keep any brain alive indefinitely after removal from a body. The pig brain study set new records, but the move into human experimentation is still likely a long way off.

Of course, there are also some huge ethical issues to consider. Could a body-less brain mean disembodied life? Should it even be possible for one being to control another’s brain, after their body is no more? What do you think about the direction science should take here? Be sure to let us know in the comments!

Ultimately, though, this is a question for which the answer can take many forms. Can the physical brain survive without a body? To some degree, yes it can. Does a body always need a brain inside it? No, it doesn’t, as nature shows. Does the brain always need a body to function more than just ticking over in that survival mode? Seemingly, yes it does. And finally, does all of that mean that headless humans could really be a future reality? That’s where we move more into pure science fiction… although the “Brain in a Vat” concept can’t be completely ruled out.