Sebastian Seung, neuroscientist and MIT professor, thinks everything can be traced back to the connectome — the complex neural network that makes up each of our brains.
One of the leaders in the emerging science of connectomics, Seung believes that mapping the connectome could provide some fundamental answers to understanding our memory, personality, even mental disorders.
But this is a gargantuan quest; we’re talking 100 billion neurons in a human brain. We spoke with Seung about his new book, “Connectome: How the Brain’s Wiring Makes Us Who We Are,” and what he calls “a turning point in human history.”
Brain World: You have said, “I am my connectome.” Have we been giving genes way too much credit?
Sebastian Seung: Most people recognize that they feel like there’s something more than genes, but they haven’t been able to put their finger on it. And so when I say, “I am my connectome,” I am saying what that extra thing could be that really defines ourselves. The connectome is a more powerful idea, because it includes the effect of genes. I’m not saying genes are not important, because genes shape who we are. A lot of that happens by shaping the connectome. Basically, so it’s also shaped by your experiences.
BW: Building the human connectome is an enormous task. What makes you think it can be done?
SS: Well, right now the way we find the connectome is by imaging brain tissue at a really, really high resolution, and then we analyze the imaging with analog computers, because there’s so much data. So I would argue that as long as computers continue to improve, we’ll be able to improve the technology that’s finding connectomes. So if computers keep on progressing the way they have over the last few decades, then we ought to be able to find the human connectome before the end of the century.
BW: If the connectome can be accurately mapped, how do you deal with the fact that neural activity is constantly changing?
SS: There are some aspects of self that are very stable and change very slowly, if they change at all. So those are the ones that we think are represented in the connectome. The connections, rather than activity. We can map out a snapshot of that. You might think of that as a snapshot of your current self. And a snapshot is a reasonable thing to do when things are changing slowly. If you snap a picture of something that is moving too rapidly it’s going to be a blur, but if it’s moving slowly you can see everything pretty clearly.
BW: Understanding the connectome can have an impact on the study of miswirings in the brain, like depression and autism. Could this mean treatments that are much more effective than what is available now?
SS: Possibly. It would just be the beginning. People have hypothesized these connectopothies, abnormalities in connections, but we can’t see them. So I would argue that if you want to develop more types of treatments it would be very important to be able to see the exact nature of the abnormality. It’s like if you want to develop better antibiotics, it helps to be able to see the bacteria that you’re trying to kill. But just being able to see myself is only the first step; there’s still a lot of other research you’d have to do. It could be a really important step. But I don’t want to overpromise. Just finding that is only one step along the road to the cures.
BW: What is it about this area of neuroscience that fascinates you?
SS: Ultimately, I would argue that every kind of important goal in life is pretty much about changing your brain. And the most acute cases of that are people who have a brain injury or brain disorder and want to change their brain. But even normal people want to learn, they want to have good relationships — everything’s about changing your brain. And so the big question is — and we have natural means of changing our brains, study harder, and so on — so the big question is what can neuroscience provide beyond the traditional methods?
BW: What do you to say to critics who say the effort could be futile, it could all fail?
SS: Well, if some endeavor doesn’t have the possibility of failing it’s usually not that interesting.