Dr. Vernon B. Mountcastle, whose studies of how brain cells conspire to process perceptions and movement laid the foundations of modern neuroscience, died last Sunday at his home in Baltimore. He was 96.

His daughter, Anne Clayton Bainbridge, said the cause was complications of the flu.

Dr. Mountcastle, known by some as the Jacques Cousteau of the cortex, began his work in the 1940s, when the brain was still very much a black box, as dark as the ocean floor. Scientists knew from studying brain injuries that certain neural regions had specialized functions — for example, to process language. But they had little idea of how brain cells, or neurons, did the work they did.

The mystery seemed especially deep when it came to so-called higher functions like thinking and perception, which are centered in the neocortex, the thin outer layer of the brain.

Dr. Mountcastle stumbled on an answer, and recognized its importance immediately. In a series of painstaking experiments, he used an electrode to record the activity of neurons in the brains of cats, as the animals responded to being touched — on the fur, for instance, or on the skin. An odd pattern emerged: Neurons that fired together in response to a specific kind of touch were stacked in columns, one on top of another.