And while their research has yielded some tantalizing insights, Bower doesn't expect definitive answers in the near future. "The notion that we're right on the edge of understanding how the brain works is nonsense," he says. "We probably don't know even one percent yet. We're still debating very fundamental things. While we have powerful techniques and a tremendous amounts of data, the brain is incredibly complex. We can take the model of a single neuron, and our most sophisticated models of a single cell require the biggest computer that has been built."

--Linda Marsa