Fidel Santamaria, a graduate student from Mexico City, has been studying the tactile sense in guinea pigs through experiments on the animals. Then he uses the data to create a computational model, in a constant feedback loop between experimentation and simulation that typifies work in the Bower lab. Santamaria, a bespectacled and friendly man with a neatly trimmed beard, studies how specific regions of the guinea pig brain respond to his stimulation of the animal's upper lips, lower lips, whisters, and cheek. It's an arduous process -- Santamaria often spends 18 hours straight in these experiments. "Sometimes I repeat the same mapping procedure 200 times in one night," says Santamaria. "I try to understand how the sensors from the skin project to the cerebellum, and how they are organized. Hopefully, with my computational model, I will understand how they code movement or process information in general from the environment."

See more at Santamaria's web site

Modeling is still in its infancy. "This kind of modeling has only really been possible over the last several years because computers are only starting to be powerful enough to run models of these types," says Dr. Bower. "In fact, we can make a model of a single neuron complex enough that it can bring the world's biggest computer to its knees. This gives you a sense of how remarkable the brain is."

--Linda Marsa