What is it Like to Be You?

A few days ago, a friend and I were day-tripping to Flushing to eat Malaysian food. She’s a philosophy student, and I'm a neuroscience student; our common ground is that we both have minds that turn on themselves. Over our meal, my friend asked me if we would ever understand what consciousness is. My own thoughts jumped to a cab ride I once took with my advisor, a prominent theoretical neuroscientist. "Consciousness…," he said, “we'll never understand that.”

Neuroscientists tend to avoid the topic, and I'm not very wise to the definitions we use to describe consciousness, but as far as I can tell, consciousness means two different things:

First, consciousness is the process by which you record and recall various states of mind. When you make a "conscious effort" to memorize a phone number, you are focusing some neural resources on the problem of storing specific perceptual data. This kind of consciousness is necessary for intelligent behavior, and despite the fact that we don't yet have intelligent machines that are very good at it, I suspect it will ultimately be understood.

Yet we also mean something else by consciousness, which maybe we can call "subjective experience." It feels a certain way to be alive and perceive the world. To see the color "red" is very different from the color "green." To feel a pinch is unlike a tickle. Philosophers call these elementary tokens of perception qualia, and one's subjective experience is a great constellation of them.

"Ahh, that's what philosophers mean by consciousness. We call that the `hard problem,’" my friend said. She told me that most philosophers agree it is possible to understand the "neural correlates of consciousness" — roughly, what a brain can be measured to be doing while it is solving various problems — but many believe we'll never understand what it feels like in someone else's brain. She brought up the philosopher Thomas Nagel who once wrote a now famous article titled, What Is It Like To Be a Bat? (PDF) in which he argued that it is impossible to extrapolate from our present mental states to those of a sonar-equipped, flying mammal. My friend and Nagel certainly make a good point. That does sound hard.

We do, however, accomplish lesser feats of brain transport. We impute intentions and desires to other people all the time. And we frequently do so by imagining ourselves in their places and proceeding to reconstruct their trains of thought. Closer to home, we remember our own lives and the memories we stored in our own brains when we had different brains. Most of the molecules in our brain cells will cycle out from our bodies throughout our lives, but we can still remember our first time in a swimming pool. (This, by the way, is a profound mystery as well.)

So the task of understanding something about another person's brain is not essentially impossible, even if it gets harder and harder as we try to situate ourselves in increasingly alien brains.

I have trouble understanding some people's political views. It is hard for me to understand what it is like to read braille, to have a stroke that makes me neglect one half of my body, or to remember every event of my entire life. Yet I can gain some understanding of these problems by constructing analogies: to remember every event in my life is probably a lot like what it is to remember many events in my life. But even better!

If you were looking at a red object, and I were looking at the same object, and some sufficiently advanced instrument indicated that our brains were processing the object in the same way, I would be happy to conclude that we are both experiencing a very similar perception. Only when you get to octopus and bat brains does the problem seem absolutely impossible. There's no way for me to experience anything like having a brain that can program its body to camouflage against its surroundings as some octopuses can. Really, there's very little that can be done there.

But philosophers have posed simpler versions of the hard problem that are actually experimentally ascertainable. In the 17th century, the writer William Molyneux, whose wife was blind, posed a famously intractable question to John Locke: Could a congenitally blind person whose sight was magically restored distinguish a cube from a sphere just by looking at them, if she already knew what those shapes felt like?

It took over three centuries for science to offer an answer. In 2011, the MIT neuroscientist Pawan Sinha, who had cured Indian children suffering from congenital cataracts, found that the children, who had not used their eyes very much before, were initially no better than chance at distinguishing rectangles and circles and other geometric shapes.

When I first heard Sinha present his work, he made it sound like a closed case. A 350 year-old philosophical problem solved! Still, I wondered, maybe the kids (who were usually not more than 12) just didn't think very hard about their task. For example, if a child has to move her eyes along a right angle to view a square, that is very similar to moving her fingers along a right angle to feel the square. It seemed like it should be possible to make some guesses based on other sensory knowledge, even if her visual discrimination were very poor. (If you're curious about the outcome, the kids eventually learned to see, although usually imperfectly.)

Very recently, the case flew open again for me. I learned about Esref Armagan, a blind man who has taught himself to paint using perspective and color. Perhaps not so incredibly, he is a more skilled painter than many sighted people are. Of course, it's not possible to restore Esref Armagan's sight, but my hunch is that he would pass Molyneux's test very quickly — within minutes — if he had a pair of working eyes.

Molyneux's problem is the question of whether you can use one sensory "modality" to understand another. It is a simplified case of the harder problem of understanding another's brain with your own. Esref may be an amazing and realistic painter, but does he know what it's like “to see” without ever having had eyes? Can I know what it's like to have sonar, what it's like to be a bat? Is my consciousness at all like yours? We have poked around the problem, we have felt its shape, and we know it is hard. We still don’t see the answer.