Synthetic Brains and Identity

Imagine if you could remove a single neuron from your brain and replace it with an artificial neuron that would mimic the original neuron’s activity. Would you still be inherently you? What if you replaced all the neurons in your brain with artificial neurons? How would this change you? In this short film, Dr. William Newsome explores the idea of brain transplants and artificial identities.

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Dr. William Newsome is an investigator at the Howard Hughes Medical Institute and professor of neurobiology at the Stanford University School of Medicine. Dr. Newsome was appointed to lead the Obama administration’s BRAIN initiative to map the brain’s 100 billion neurons and trillions of connections.


Dr. William Newsome: A brain transplant, if it were possible, is the only transplant surgery where you’d rather be the donor than the recipient. You have to think about that one for a minute. So, if I get a new heart, I’m still me. If I get new lungs or if I get a new prosthetic leg, I’m still me. But if I get a new brain inside this head and this brain goes off someplace else, what is me?

Let’s imagine that we can take one neuron out of my brain, and we could replace it with a little artificial neuron made of silicon or something, and that artificial neuron mimics the function of the natural neuron in all ways that we can measure. So, it has the same 1,000 connections with the same strength. That neuron has the ability to change its synaptic connection weights with the other neurons as a function of learning, the way the natural neuron does. And then the question is, if I have all but a hundred billion neurons are natural and the one is artificial, am I still me?

And I think the answer, obviously, is yes. Then you just keep doing that experiment. You keep replacing them one at a time. A hundred billion neurons replacements later, you have a completely in silicon brain, and would that brain be conscious? Would that brain be human? Would that brain be Bill in a real, deep, meaningful sense of the word? I think the answer’s yes. I don’t think there’s anything magical about carbon, nitrogen, hydrogen, and oxygen as building blocks. What’s magical is the way those elements are hooked together, the way that they’re organized, and the information-processing capabilities that get endowed by virtue of that high-level organization.

  • Course Categories: General Theology, Pastoral Theology
  • Science Topics: Neuroscience, Brain, & Mind
  • Tags:
    neuroscience, science and religion, synthetic brains, artificial neurons, Dr. William Newsome

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