Most neuroscientists believe that our "self"— the core thoughts, memories, and emotions that make us who we are — resides in the intricate connections of the three-pound, soft, wrinkly, and squishy organ that we call our brain.
And some researchers, especially those who fall into the "futurist" category, believe that if we could replicate the exact structure of the brain, we might be able to create the sort of artificial intelligence that might eventually offer the power and nuance of the human mind.
"I actually think it's a possibility that we'll have a simulation of a brain before we understand it," neuroscientist David Eaglemantold Tech Insider in a recent interview, though he stressed that this is in the realm of speculation, not fact.
As far out there as this is (and this is pretty far out), we might even be able to create some sort of way for a consciousness to reside in that external structure, allowing for a sort of digital immortality. Theoretically, of course, provided our concept of the brain basically working like a biological computer is true.
But we're still very far from understanding the brain. It's shocking, in many ways, to think of how little we actually know about how the brain works. We don't understand how memories are stored; we don't know how our brains create meaning from the chaotic stimuli of the world; we don't know how intelligence works; and we're still struggling to understand the roots of mental illnesses.
"When I walked into my first society of neuroscience meeting, I saw all these high I.Q. people and thought, 'by the time I'm done with grad school, this is all going to be solved,'" Eagleman said. "It turns out, 20 years later, I can point to all sorts of technological innovations, but the big questions that drew me into neuroscience are all still there."
Copying the brain
Eagleman explained why he thinks it might be possible to develop technology that allows us to replicate the brain before we've really filled in all the details of its functioning. As he put it: "You can Xerox a book in a language you don't understand."
Working toward that replication may even help unlock some of the many remaining mysteries of neuroscience.
The question is how fine a resolution we need. "Any given brain cell is connected to about 10,000 of its neighbors, and [the question of] which neuron is connected to which is very specific," he said.
Even when we can eventually visualize and model a brain of that complexity, we don't know if that will be sufficient. Eagleman said that perhaps we won't really be able to model a brain until we understand the way the proteins in the membranes of these neural cells interact or until we understand exactly how hormones or other chemicals affect neural processes.
But if in the end, the only thing stopping us from building an exact replica of a human brain is computational power — the ability to build a system that can process and emulate this whole structure — Eagleman suspects "we'll get to the point where it's not the issue."