In “The Ultimate Brain Quest” (Wall Street Journal, February 4, 2012), Daniel J. Levitin reviewsreviews Sebastian Seung ‘s new book, Connectome, noting, “Deciphering how human thought works is mind-bendingly difficult, but researchers now know where to start”:
Neuroscientists posit that all of our hopes, desires, beliefs and experiences are encoded in the brain as patterns of neural firings. Just how this happens is not precisely understood, as the author attests, but we have made great strides in understanding how neurons communicate with one another. Progress has also been made in mapping which brain systems control which kinds of operations (my own field of research): One system is responsible for lifting your foot, another senses the pain when you stub your toe; one system helps you to solve arithmetic problems, another enjoys “La Bohème.” A new approach to studying brains and individual differences involves making maps of how neurons connect to one another. Following the term genome, these are called connectomes.
As it happens,
Even in the current speculative realm, the connectome is a fascinating, occasionally frustrating, subject. One view is that each connectome or connectivity map will give rise to one and only one brain state and that different connectomes cannot give rise to the same state. Yet the widespread use of pharmaceutical agents such as Prozac and Ritalin suggests otherwise—that knowing the connectome is unlikely to tell us all we need to know about a person’s thoughts, feelings, opinions and personality.
There is certainly no reason to expect the kind of certainty the first group hopes for. What they would like to know can’t even be described easily.
Despite the fact that we have different brains and different neuronal configurations, when you and I smell a skunk it seems likely that we have equivalent mental states that lead to the same conclusions. Knowing the wiring is a crucial operation in understanding the nature of thought, but it seems not to be enough; we also need to know the precise chemical soup du jour in the brain. And one more additional, crucial step is understanding which types of experiences and environmental events can change the brain’s wiring and in what ways.
And for which people, one might add. It is astonishing how the same experience can shape lives differently.
If the connectome doesn’t kill neuroscience, it may teach it something.
Hat tip: Stephanie West Allan at Brains on Purpose