A June 9, 2022 news item on Nanowerk featured the question,

Reader question: I am 59 years old, and in reasonably good health. Is it possible that I will live long enough to put my brain into a computer? [from] Richard Dixon.

We often imagine that human consciousness is as simple as input and output of electrical signals within a network of processing units – therefore comparable to a computer. Reality, however, is much more complicated. For starters, we don’t actually know how much information the human brain can hold.

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Guillaume Thierry’s (Professor of Cognitive Neuroscience, Bangor University in Bangor, Wales, UK) June 9, 2022 essay (on The Conversation) provides the rest of this fascinating answer (Note: Links have been removed),

Two years ago, a team at the Allen Institute for Brain Science in Seattle, US, mapped the 3D structure of all the neurons (brain cells) comprised in one cubic millimetre of the brain of a mouse – a milestone considered extraordinary.

Within this minuscule cube of brain tissue, the size of a grain of sand, the researchers counted more than 100,000 neurons and more than a billion connections between them. They managed to record the corresponding information on computers, including the shape and configuration of each neuron and connection, which required two petabytes, or two million gigabytes of storage. And to do this, their automated microscopes had to collect 100 million images of 25,000 slices of the minuscule sample continuously over several months.

Now if this is what it takes to store the full physical information of neurons and their connections in one cubic millimetre of mouse brain, you can perhaps imagine that the collection of this information from the human brain is not going to be a walk in the park.

Data extraction and storage, however, is not the only challenge. For a computer to resemble the brain’s mode of operation, it would need to access any and all the stored information in a very short amount of time: the information would need to be stored in its random access memory (RAM), rather than on traditional hard disks. But if we tried to store the amount of data the researchers gathered in a computer’s RAM, it would occupy 12.5 times the capacity of the largest single-memory computer (a computer that is built around memory, rather than processing) ever built.

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… If you were paying attention when I described the extraordinary achievement of researchers who managed to fully store the 3D structure of the network of neurons in a tiny bit of mouse brain, you will know that this was done from 25,000 (extremely thin) slices of tissue.

The same technique would have to be applied to your brain, because only very coarse information can be retrieved from brain scans. Information in the brain is stored in every detail of its physical structure of the connections between neurons: their size and shape, as well as the number and location of connections between them. But would you consent to your brain being sliced in that way?

Even if [you] would agree that we slice your brain into extremely thin slices, it is highly unlikely that the full volume of your brain could ever be cut with enough precision and be correctly “reassembled”. The brain of a man has a volume of about 1.26 million cubic millimetres.

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There are more technical problems according to Thierry (Note: Links have been removed),

After we die, our brains quickly undergo major changes that are both chemical and structural. When neurons die they soon lose their ability to communicate, and their structural and functional properties are quickly modified – meaning that they no longer display the properties that they exhibit when we are alive. But even more problematic is the fact that our brain ages.

From the age of 20, we lose 85,000 neurons a day. But don’t worry (too much), we mostly lose neurons that have not found their use, they have not been solicited to get involved in any information processing. This triggers a programme to self-destruction (called apoptosis). In other words, several tens of thousands of our neurons kill themselves every day. Other neurons die because of exhaustion or infection.

This isn’t too much of an issue, though, because we have almost 100 billion neurons at the age of 20, and with such an attrition rate, we have merely lost 2-3% of our neurons by the age of 80. And provided we don’t contract a neurodegenerative disease, our brains can still represent our lifelong thinking style at that age. But what would be the right age to stop, scan and store?

Would you rather store an 80-year-old mind or a 20-year-old one? Attempting the storage of your mind too early would miss a lot of memories and experiences that would have defined you later. But then, attempting the transfer to a computer too late would run the risk of storing a mind with dementia, one that doesn’t quite “work” as well.

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There are other technical issues but this is my favourite set of issues,

I may have a useful, albeit unexpected, answer to give you after all. I shall assume that you would want to transfer your mind to a computer in the hope of existing beyond your lifespan, that you’d like to continue existing inside a machine once your body can no longer implement your mind in your living brain.

If this hypothesis is correct, however, I must object. Imagining that all the impossible things listed above were one day resolved and your brain could literally be “copied” into a computer – allowing a complete simulation of the functioning of your brain – at the moment you decide to transfer, Richard Dixon would have ceased to exist. The mind image transferred to the computer would therefore not be any more alive than the computer hosting it.

That’s because living things such as humans and animals exist because they are alive. You may think that I just stated something utterly trivial, verging on stupidity, but if you think about it there is more to it than meets the eye. A living mind receives input from the world through the senses. It is attached to a body that feels based on physical sensations. This results in physical manifestations such as changes in heart rate, breathing and sweating, which in turn can be felt and contribute to the inner experience. How would this work for a computer without a body?

All such input and output isn’t likely to be easy to model, especially if the copied mind is isolated and there is no system to sense the environment and act in response to input. The brain seamlessly and constantly integrates signals from all the senses to produce internal representations, makes predictions about these representations, and ultimately creates conscious awareness (our feeling of being alive and being ourselves) in a way that is still a total mystery to us.

Without interaction with the world, however subtle and unconscious, how could the mind function even for a minute? And how could it evolve and change? If the mind, artificial or not, has no input or output, then it is devoid of life, just like a dead brain.

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So no, no and no. I have tried to give you my (scientifically grounded) take on your question and even though it is a definite no from me, I hope to have helped alleviate your desire to ever have your brain put into a computer.

I wish you a long and healthy life, Richard, because that definitely is where your mind will exist and thrive for as long as it is implemented by your brain. May it bring you joy and dreams – something androids will never have.

I recommend reading the essay (if you have time) or even going to Thierry’s June 9, 2022 essay to view the embedded video about the mouse brain work mentioned at the beginning.

As to where this ‘reader question’ came from, this is a special ‘The Conversation’ series,

This article is part of Life’s Big Questions
The Conversation’s series, co-published with BBC Future, seeks to answer our readers’ nagging questions about life, love, death and the universe. We work with professional researchers who have dedicated their lives to uncovering new perspectives on the questions that shape our lives.

BBC being the British Broadcasting Corporation.