Montague began his scientific life in mathematics and biophysics, but foresight warned him that physics was not the wave of the future. While dabbling in a quantum chemistry project, his thoughts turned to the brain. Why not put math to use in comprehending cognition as well as the cosmos? He began to work on computational modeling of brain processes, and then proceeded to peer deep into real brains, exploiting a technology provided by physics to revolutionize psychology.
Brain scanners are so familiar today that it’s hard to remember that a generation or so ago many scientists still considered the brain to be forever inscrutable. The behaviorist psychology of the early 20th century, proselytized by B. F. Skinner, had left its imprint on general beliefs about brain and behavior. Brains could not be observed in action, so only the behaviors that the brain produced mattered to science, the behaviorists contended. It turned out to be a misguided notion of both science and the brain.
By the 1970s, imaginative new technologies had begun to make the brain transparent to clever neurovoyeurs. Radioactive atoms could be attached to critical molecules, allowing their activity to be observed in living brains, providing clues to what brains were doing while animals were behaving. Later methods dispensed with the radioactivity, using magnetic fields to jostle molecules in the blood that flowed through brain tissue. Ultimately this method, known as magnetic resonance imaging, or MRI, became widely used in medicine to “see” beneath the skin. And a variant of MRI technology was adopted by researchers in neuroscience to watch brains in action.5
“It can make a movie of the dynamic blood flow changes in every region of your brain,” Montague said. And blood flow has been shown to be tightly linked to neural activity—active neurons need nourishment, so that’s where the blood goes. You can watch how patterns of activity change in different parts of the brain as its owner performs various behaviors.
Consequently, the old limits on which aspects of the brain could be studied and understood had dissolved, Montague explained, as a new wave of neuroscientists embraced the imaging