As science progresses further and further along, it's remarkable how little we still understand about the big questions of consciousness, which are simple enough to ask, but downright confounding to answer. If it's any consolation, we are pretty sure that we're looking in the right place — the brain. Although the more we study the brain, the more it seems like it's among the most complicated things in the known universe, full of an unimaginably high number of connections.

Sebastian Seung, an MIT professor of computational neuroscience, believes that the secret to understanding how the brain works lies in finding all of those connections and mapping them, and he explores this idea in “Connectome,” his fascinating new book. It seems simple enough that we should understand how the brain works once we figure out all of those connections interact, but that's even less elegant than trying to understand the way weather works by keeping track of all of the particles in the atmosphere.

Still, for confounding questions like how we learn, perhaps a brute force method may not be such a bad idea.

The idea of a connectome, or map of the brain, forms the backbone of the book. That's not all it's about, but it does provide structure for Seung to address some of the questions that many readers will have about the brain and explain some interesting experiments, including one that suggests that individual neurons may be responsible for recognizing specific faces (the “Jennifer Aniston neuron,” for instance).

Seung's book also addresses questions of nature and nurture by explaining that things aren't so simple that they can be so easily categorized. Brains are far too complicated to be explicitly described in our genes, but that doesn't mean our genes can't build them. As a result, identical twins have unidentical brains, since their experiences have been different. At the same time, they’re more similar than fraternal twins as shown through personality and IQ tests. In other words, both nature and nurture seem to have an effect on the brain.

The final portion of the book may be the most exciting for many readers, though it's also the most speculative. In it, Seung discusses immortality and two different ways of achieving it, neither of which seem particularly appealing. The first involves cryonics, or freezing the body of a near-death patient in the hopes that future generations will be able to unfreeze and cure him. There are a lot of “if's” in the idea, but since we're playing with your life and the risks are negligible, it's worth a shot.

If you lose, you die, but if you don't play, you also die. The second involves transferring your brain to a computer, where a virtual you would live forever, but if it's a true and exact copy of your brain, is it really virtual? Seung takes the correct approach here in presenting these as speculative ideas that may or may not pan out, rather than committing to them as absolute certainties. If he's learned anything by studying the brain, it's to be cautious in predicting the future of our understanding.

“Connectome” is a book about a topic that we're only slowly beginning to understand. The brain may very well be the most difficult mystery for science to crack, continuing to baffle us even as it solves mysteries of the entire universe. Seung does a good job of putting things in perspective, and manages to engage the reader while doing it, but if the book makes anything clear, it's that we've still got a long way before we understand that hunk of grey matter that exists between our ears.