PERSON
Terrence Sejnowski
Physicist-turned-neuroscientist who co-invented the Boltzmann machine, built NETtalk, and helped found computational neuroscience—the man who built the early learning machines by hand, and has spent forty years refusing to mistake what they achieved for what they understood.
Terrence Sejnowski is one of a small number of people who can say, without exaggeration, that they helped build the thing the rest of us are now arguing about. Trained as a physicist at Princeton under John Hopfield, he crossed into neurobiology at Harvard Medical School and never fully left either world, holding throughout his career the double question: how does the brain learn, and how can a machine be made to learn the same way? In 1985 he co-invented the
Boltzmann machine with Geoffrey Hinton—a stochastic, energy-based network that learned by reducing the gap between what it dreamed on its own and what the world had shown it—and two years later built
NETtalk, a program that learned to read English aloud starting from babble, which people who heard it described as watching a machine cross a line they had assumed only living things could cross. He helped found
computational neuroscience as a field, started the journal
Neural