During the training of Boltzmann Machines there are periods when the network has no clamped inputs, a phase not unlike human sleep. In 1983 papers by John Hopfield and Francis Crick, written from entirely different perspectuves, suggested that forms of sleep/dreaming were valuable for neural networks to learn effectively.
Used in Chap. 22: page 349
Used in glossary entries: Boltzmann machine, Francis Crick, Hopfield, John, neural network