"We do have free will," he says, but it is biologically based: "It's one's ability to respond to things of greater and greater abstraction."

A biologically based understanding of the brain "may influence our whole philosophy so that we don't think in such a mystical way," he adds.

According to Hubel and Wiesel, their findings also shed light on the classic question of "nature vs. nurture"--whether perception and behavior are instinctive or learned in the environment. Since specific cells naturally recognize simple shapes, "it seems that at birth you are endowed with an eye for details," Wiesel says, adding, "The neuroconnectors are there."

"If you don't nurture these connection between the eye and visual cortex properly," if they are not used within a "critical period after birth, they will be lost," Wiesel says.

That discovery may aid the prevention of childhood blindness. And Wiesel says the idea of a "critical period" could perhaps apply to much more complicated brain function. "Deprivation of attention, emotion, what a mother provides for a child, emotional contact with siblings--there is evidence that kids lacking these things develop more slowly," he explains, adding, "Perhaps it is important to stimulate people to use their intellectual and emotional resources early."

Ultimately, Hubel says, knowledge of the brain "may help us to learn how to control our behavior, how to educate ourselves."

Or maybe it won't. Wiesel cautions that scientists may never fully understand the brain. "We may not be able to pinpoint all the solutions so clearly. At this stage we are only defining the variables," he says, adding, "The most exciting work is ahead of us."

But also ahead for Hubel and Wiesel is a December trip to Stockholm, for Nobel lectures and award ceremonies. "I don't think [the prize] means anything. I don't take it seriously," the Swedish-born and educated Wiesel says.

"I look forward to when I can stop doing press conferences and interviews and get back to doing experiments," he adds.