In 2018, billionaire Silicon Valley entrepreneur Sam Altman paid a startup called Nectome $10,000 to preserve his brain after he dies and, when the technology to do so becomes available, to upload his memories and consciousness to the cloud.
This prospect, which was recently popularised in Amazon Prime’s sci-fi comedy series Upload, has long been entertained by transhumanists. Although theoretically possible, it is rooted in the flawed idea that the brain is separate from the body, and can function without it.
The idea that the mind and brain are separate from each other is usually attributed to the 17th-century mathematician and philosopher René Descartes, who believed that the body is made of matter, and the mind of some other, non-physical substance.
Modern brain research rejects the distinction between the physical and the mental. Most neuroscientists agree that what we call “the mind” is made of matter. The mind is hard to define, but the consensus now is that it emerges from the complex networks of cells in the brain.
But most people still view the mind and brain as being distinct from the body. In 2016, four prominent brain researchers published an article summarising what we know about consciousness. It begins: “Being conscious means that one is having an experience … to see an image, hear a sound, think a thought or feel an emotion.”
It is, however, becoming increasingly clear that the mind/brain and body are intimately linked, and that the body influences our thoughts and emotions. Being conscious does not just mean having awareness of the outside world. It means being aware of one’s self within one’s surroundings. The way we experience our body is central to how we perceive our self.
Phantom limbs are a striking demonstration of the importance of the body for self-consciousness. They were described in the mid-16th century by the barber-surgeon Ambroise Paré, who reportedly amputated several hundred limbs a day during the Italian war of 1542-46.
“Verily it is a thing wondrous, strange and prodigious,” he wrote. “The patients who have many months after the cutting away of the leg grievously complained that they yet felt exceeding great pain of that leg cut off.” At that time, however, few survived the operation, so the phenomenon was seen only rarely, and dismissed as a delusion.
Advances in medicine and military technology changed this. The invention of a bullet called the Minié ball with its greater accuracy, range, and muzzle velocity, increased the number of amputations, while the introduction of anaesthetics and antiseptics improved the survival rates of soldiers who went under the knife.
And so it was that the neurologist Silas Weir Mitchell, who amputated countless arms and legs on the battlefields of the American civil war, came to see that phantom limbs are the rule rather than an exception, experienced by the vast majority of amputees.
The medical community was still sceptical of the phenomenon, however, so Mitchell initially described his observations as a short story, The Case of George Dedlow, published in the Atlantic Monthly in July 1866. The fictional titular character was a composite of the hundreds of thousands of soldiers who were maimed and mutilated during the conflict. He lost all four limbs, one by one, to become “a useless torso, more like some strange larval creature than anything of human shape”, reduced to “[a] fraction of a man”.
Mitchell’s story was so vivid that readers took it as factual, and believed that he was a real patient being treated at Philadelphia’s South Street “Stump” hospital. Many wrote him letters of support, some tried to visit him,…
Read More: Is the body key to understanding consciousness? | Consciousness